Plaque It!
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[0001] This application claims priority under 35 USC 119 from Japanese Patent Application, No. 2003-135564, the disclosure of which is incorporated by reference herein.
[0002] 1. Field of the Invention
[0003] The present invention relates to a through anchor which is applied to a seat belt device for a vehicle, and around which a webbing for restraining a vehicle occupant is trained, and which supports the webbing at a vehicle body, and to a method of manufacturing the through anchor.
[0004] 2. Description of the Related Art
[0005] A three point seat belt device using a continuous webbing is known as a seat belt device for a vehicle.
[0006] In this type of seat belt device, one end portion of the webbing is anchored at a retractor, and the other end portion of the webbing passes through a through anchor and is anchored to an anchor plate. When a vehicle occupant applies the webbing to himself/herself, he/she engages a tongue plate, which is disposed at an intermediate portion of the webbing between the anchor plate and the through anchor, with a buckle device. The webbing is thereby pulled out from the retractor and set in a state of being applied to the vehicle occupant.
[0007] The through anchor, around which the webbing is trained and which is for supporting the webbing at the vehicle body as described above, is generally structured such that a resin material is integrally molded with a metal main body portion (a metal plate). In this way, the edge portions and the like of the metal main body portion are covered and are not exposed to the exterior. Moreover, in such a through anchor, in order for the webbing to be drawn-out and taken-up smoothly, a structure is known in which a resin piece, which is formed of a synthetic resin material such as polyacetal or high molecular weight polyethylene or the like, is fixed to the portion of the through anchor along which the webbing slides, so as to decrease the coefficient of friction with the webbing.
[0008] However, in a through anchor having the above-described structure, when a large load is applied to the webbing at the time when the vehicle rapidly decelerates, because the coefficient of friction of the resin piece is low, there are cases in which the webbing slips laterally within the insert-through hole and moves toward and gets stuck at one end of the insert-through hole, such that so-called jamming occurs.
[0009] Thus, the forming of plural grooves in the surface of the resin piece is know as a means for preventing jamming while ensuring good slidability of the webbing (see, for example, Japanese Utility Model Application Laid-Open (JP-U) No. 1993-44719).
[0010] However, in the through anchor disclosed in JP-U No. 1993-44719, the grooves in the surface of the resin piece are formed in a direction which is inclined toward the front of the vehicle with respect to the direction orthogonal to the width direction of the webbing (i.e., the grooves are formed in a direction orthogonal to the width direction of the webbing at the time when the webbing is in its state of usual application to the body of the vehicle occupant). Accordingly, there are cases in which the webbing slips laterally toward the front of the vehicle within the insert-through hole due to the component of force, which is directed toward the front of the vehicle, of the force applied from the grooves to the webbing, and jamming cannot be reliably suppressed.
[0011] The present invention is conceived of in consideration of the above-described circumstances. The present invention is to provide a through anchor which can reliably prevent jamming while ensuring good slidability of a webbing, and a method of manufacturing the through anchor.
[0012] A first aspect of the present invention is a through anchor for supporting, at a vehicle, a webbing for restraining a vehicle occupant, the through anchor including, a main body portion which is formed of metal, and in which is formed an insert-through hole through which the webbing is inserted, a piece that is assembled to a peripheral edge of the insert-through hole of the main body portion and structuring a portion of the insert-through hole, a surface of the piece being a region around which the webbing is trained, and the piece having plural grooves in the surface, and a covering portion that is molded, together with the piece, integrally at a periphery of the insert-through hole of the main body portion, and covering the corresponding region, wherein, among the grooves of the surface of the piece, at least the configurations of the grooves at a region which is disposed at a front side of the vehicle and at an inner side of a vehicle compartment run along a direction of application of the webbing to a vehicle occupant and are formed so as to smoothly curve toward a rear of the vehicle.
[0013] In the through anchor of the first aspect, the piece is assembled to a peripheral edge of the insert-through hole formed in the metal main body portion, and structures a portion of the insert-through hole. The covering portion is, together with the piece, integrally molded to the periphery of the insert-through hole of the main body portion. By attaching this through anchor either directly or indirectly to a predetermined position within a vehicle (e.g., a center pillar or the like), the longitudinal direction intermediate portion of the webbing, which is inserted through the insert-through hole of the main body portion, is supported while being trained around the surface of the piece. Accordingly, because the webbing slides along the surface of the piece at the time of pulling-out or taking-up the webbing, the pulling-out or taking-up of the webbing can be carried out smoothly.
[0014] The plural grooves are formed in the surface of the piece. Therefore, for example, when inertial force directed toward the front of the vehicle is applied to the body of the vehicle occupant in a state in which the vehicle rapidly decelerates and pulling-out of the webbing is locked by a webbing retractor, the webbing trained around the surface of the piece slides in a state of being tightly fit against the plural grooves of the surface of the piece.
[0015] In particular, when a very large load is applied to the webbing, the webbing slides in a state of being strongly fit tightly to the grooves at the region of the surface of the piece, which region is disposed at the front of the vehicle and at the vehicle compartment inner side (the vehicle occupant side). Therefore, the direction of sliding of the webbing is restricted (guided) by the grooves at this region.
[0016] Here, in the present through anchor, the configurations of at least the grooves at the region of the surface of the piece, which region is disposed at the front side of the vehicle and at the inner side of a vehicle compartment, run along the direction of application of the webbing to the vehicle occupant and are formed so as to smoothly curve toward the rear of the vehicle. Therefore, the webbing, which is sliding while being guided by the grooves of the surface of the piece, slides while the direction of sliding thereof is pulled to return (corrected) toward the rear of the vehicle. (In other words, the grooves are formed such that, in the force which the webbing receives from the grooves of the surface of the piece, only a slight component of force directed toward the front of the vehicle is generated.) Accordingly, the present through anchor can reliably prevent lateral slippage of the webbing toward the front of the vehicle in the insert-through hole at the time when the vehicle rapidly decelerates.
[0017] In this way, the through anchor of the first aspect can reliably prevent jamming while ensuring good slidability of the webbing.
[0018] A method of manufacturing a through anchor of a second aspect of the present invention is a method of manufacturing a through anchor which is for supporting, at a vehicle, a webbing for restraining a vehicle occupant. The method includes, fabricating a main body portion which is formed of metal and has a through hole, fabricating a piece having a surface around which the webbing is trained, forming plural grooves, which run along a direction of application of the webbing to a vehicle occupant and which smoothly curve toward a rear of the vehicle, at least at a region of the surface of the piece which region is disposed at a front side of the vehicle and at an inner side of a vehicle compartment, assembling the piece to a peripheral edge of the through hole of the main body portion, and molding a covering portion, together with the piece, the covering portion covering the corresponding region, integrally to a periphery of the through hole of the main body portion, so as to form an insert-through hole through which the webbing is inserted.
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[0040] The structure of a through anchor
[0041] As shown in these drawings, the through anchor
[0042] The main body portion
[0043] An insert-through plate portion
[0044] A piece
[0045] An extending portion
[0046] The piece
[0047] Note that, as shown in
[0048] On the other hand, as shown in
[0049] As shown in
[0050] Plural stripe-like grooves
[0051] Here, for example, let us suppose a state in which the through anchor
[0052] Note that, in a state in which, for example, the through anchor
[0053] Next, operation of the present embodiment will be described.
[0054] At the through anchor
[0055] Accordingly, when the webbing
[0056] Note that, in the present embodiment, it is supposed that the through anchor
[0057] The plural grooves
[0058] In the conventional art, for example, as in the case of a through anchor
[0059] In contrast, in the through anchor
[0060] Namely, the through anchor
[0061] In this way, in the through anchor
[0062] The grooves
[0063] In the state in which the piece
[0064] The positioning grooves
[0065] In the above-described embodiment, the piece
[0066] In the above-described embodiment, the through anchor
[0067] Next, modified examples of the piece
[0068] (First Modified Example)
[0069] A first modified example shown in
[0070] In the top view shown in
[0071] (Second Modified Example)
[0072] In a second modified example shown in
[0073] In the top view shown in
[0074] (Third Modified Example)
[0075] In a third modified example shown in
[0076] In the top view shown in
[0077] (Fourth Modified Example)
[0078] In a fourth modified example shown in
[0079] In the top view shown in
[0080] (Fifth Modified Example)
[0081] In a fifth modified example shown in
[0082] In the top view shown in
[0083] Note that the pieces
[0084] As described above, in accordance with the through anchor of the present invention, jamming can be reliably prevented while good slidability of the webbing is ensured.
[0085] Note that, in the through anchor of the present invention, it is preferable that the piece have, at a region of the surface thereof corresponding to the central portion of the webbing in the width direction, a concave portion whose surface is smooth.
[0086] In the above-described through anchor, the concave portion whose surface is smooth is formed in the surface of the piece having plural grooves, at a region corresponding to the central portion of the webbing in the width direction thereof. Therefore, when tension is applied to the webbing when the vehicle rapidly decelerates, the webbing fits tightly to the regions where the grooves are formed at both sides of the concave portion. Thus, the surface pressure of the webbing with respect to the surface of the piece is high, and the ability of the webbing to fit tightly to the grooves of the surface of the piece is good. In this way, it is possible to even more reliably prevent the webbing from slipping laterally within the insert-through hole when the vehicle rapidly decelerates.
[0087] Further, it is preferable that the through anchor of the present invention have a convex portion provided at the surface of the main body portion at the periphery of the insert-through hole, and an engaging portion which is provided at the piece and which engages with the convex portion of the main body portion when the piece is assembled to the main body portion.
[0088] At the above-described through anchor, the convex portion is provided at the surface of the main body portion at the periphery of the insert-through hole, and the engaging portion, which engages with the convex portion when the piece is assembled to the main body portion, is provided at the piece. Therefore, joggling of the piece, which is assembled to the main body portion, with respect to the main body portion is suppressed. In this way, the precision of molding at the time of integrally molding the covering portion in the state in which the piece is assembled to the main body portion is improved.
[0089] Further, in the through anchor of the present invention, it is preferable that the piece have a positioning portion which engages with an eject pin of a mold at the time when the covering portion is molded.
[0090] In this through anchor, a positioning portion is provided at the piece, and the positioning portion engages with an eject pin of a mold when the covering portion is molded. In this way, when the piece is assembled to the main body portion, and the main body portion is attached to a predetermined position of a mold, and the covering portion is molded, positional offset of the piece (the main body portion) with respect to the mold can be prevented. Therefore, the accuracy of molding the through anchor is improved.