The present invention relates to belt guide anchors that are supported by vehicle bodies such as pillars and guide seat belts in seat belt units to shoulders of occupants, and relates to seat belt units including the belt guide anchors.
Seat belt units installed in vehicle seats in automobiles and the like have been used for restraining occupants with seat belts in the units in emergency situations such as collisions in which a large deceleration acts on the vehicles. Among such seat belt units, those supported by pillars of vehicle bodies and including belt guide anchors that guide seat belts such that the seat belts are slidable, for example, have been discussed in, for example, Japanese Unexamined Patent Application Publication No. 2002-200964.
According to a belt guide anchor described in Japanese Unexamined Patent Application Publication No. 2002-200964, a seat belt drawn from a seat belt retractor is folded back at the belt guide anchor and guided to a shoulder of an occupant so as to be fitted to the occupant. With this, the seat belt can restrain the occupant at a correct position.
In some cases, seat belt retractors in seat belt units need to be disposed far rearward of occupants depending on layouts of vehicles. When the seat belt retractors are disposed at rear positions in this manner, belt opening angles between portions of seat belts before being folded at belt guide anchors (i.e., portions adjacent to the seat belt retractors) and portions of the seat belts after being folded at the belt guide anchors (i.e., portions adjacent to the occupants) become large.
However, in the belt guide anchor described in Japanese Unexamined Patent Application Publication No. 2002-200964, molded resin portions adjoining a belt insertion hole are made thick, and project in the thickness direction of the belt guide anchor (inward and outward directions at a side of a vehicle) by a large amount. These expanded portions can increase the radii of curvature of the molded resin portions adjoining the belt insertion hole such that a seat belt can be smoothly slid at these portions.
When the expanded portions are formed in the vicinity of the belt insertion hole in this manner and the belt opening angle between the portion of the seat belt adjacent to the seat belt retractor and that adjacent to an occupant is increased as described above, the seat belt is pressed into contact with these expanded portions. Therefore, friction between the seat belt and the expanded portions of the belt guide anchor when the seat belt is drawn out is increased, and the seat belt cannot be smoothly drawn out. Furthermore, the belt guide anchor can be rotated by the frictional force, and an offset (jamming) of the seat belt can occur more easily. Accordingly, when the seat belt retractor is disposed in a vehicle in the above-described layout, the handling operability of the seat belt can be impaired.
Degradation of the operability of the seat belt can be prevented by increasing the width of the belt insertion hole of the belt guide anchor. However, when the width of the belt insertion hole is increased, the movement of the seat belt cannot be regulated in the width direction. Thus, the offset can easily occur in a similar manner.
Accordingly, an object of the present invention is to provide a belt guide anchor capable of improving handling operability of a seat belt even when a belt opening angle between a portion of the seat belt adjacent to a retractor and that adjacent to an occupant is increased, and to provide a seat belt unit including the belt guide anchor.
To solve the above-described problems, a belt guide anchor according to a first invention of the present invention, having a belt insertion hole into which a seat belt drawn from a seat belt retractor is fitted so as to be slidable and expanded portions disposed on both surfaces of the belt guide anchor facing the interior and exterior of a vehicle adjacent to the belt insertion hole, and guiding the seat belt to an occupant via the belt insertion hole, includes a first thin part disposed in the expanded portion on the surface of the belt guide anchor facing the interior of the vehicle at a lower position of a part of the belt insertion hole facing the front side of the vehicle when the belt guide anchor is attached to the vehicle body, the thickness of the first thin part being smaller than that of the expanded portion located at a lower position of a part of the belt insertion hole facing the rear side of the vehicle when the belt guide anchor is attached to the vehicle body; and a second thin part disposed in the expanded portion on the surface of the belt guide anchor facing the exterior of the vehicle at a lower position of the part of the belt insertion hole facing the rear side of the vehicle when the belt guide anchor is attached to the vehicle body, the thickness of the second thin part being smaller than that of the expanded portion located at a lower position of the part of the belt insertion hole facing the front side of the vehicle when the belt guide anchor is attached to the vehicle body.
Moreover, according to a second form of the present invention, the first thin part disposed on the surface of the belt guide anchor facing the interior of the vehicle is thinner than a part of the expanded portion facing the rear side of the vehicle at a position symmetrical to the first thin part disposed in the expanded portion facing the front side of the vehicle with respect to a vertical center line when the belt guide anchor is attached to the vehicle body, and the second thin part disposed on the surface of the belt guide anchor facing the exterior of the vehicle is thinner than a part of the expanded portion facing the front side of the vehicle at a position symmetrical to the second thin part disposed in the expanded portion facing the rear side of the vehicle with respect to the vertical center line when the belt guide anchor is attached to the vehicle body.
Furthermore, according to a third form of the present invention, the thin parts disposed on the surfaces of the belt guide anchor facing the interior and exterior of the vehicle are both recessed portions.
On the other hand, a seat belt unit according to a fourth form of the present invention includes a seat belt to be worn by an occupant; a seat belt retractor that retracts the seat belt such that the seat belt can be drawn out and prevents the seat belt from being drawn out in an emergency situation; a belt guide anchor that guides the seat belt drawn from the seat belt retractor to the occupant; a tongue supported by the seat belt passing through the belt guide anchor so as to be slidable; and a buckle attached to a vehicle body or a vehicle seat, the tongue being engaged with the buckle so as to be detachable. The belt guide anchor is the belt guide anchor according to any one of the first to third forms of the present invention.
In accordance with the belt guide anchor having the above-described structure according to the present invention, the first thin part is formed in the expanded portion facing the front side of the vehicle on the surface of the belt guide anchor facing the interior of the vehicle at the position adjoining the part of the belt insertion hole facing the front side of the vehicle, and the second thin part is formed in the expanded portion facing the rear side of the vehicle on the surface of the belt guide anchor facing the exterior of the vehicle at the position adjoining the part of the belt insertion hole facing the rear side of the vehicle. Thus, when a portion of the seat belt adjacent to the occupant passing through the belt insertion hole is inclined at a maximum angle and extends downward and forward of the vehicle, a side end of the portion of the seat belt adjacent to the occupant facing the front side of the vehicle comes into light contact with the first thin part in the belt guide anchor. In addition, when a portion of the seat belt adjacent to the retractor to be passing through the belt insertion hole is inclined at a maximum angle and extends upward and forward of the vehicle, a side end of the portion of the seat belt facing the rear side of the vehicle comes into light contact with the second thin part in the belt guide anchor and the peripheral portions thereof.
With this structure, the friction between the seat belt and the thin parts in the expanded portions can be reduced, and the occupant can smoothly draw the seat belt out when he/she wears the seat belt. In this case, even when the seat belt is drawn from a rear position of the vehicle significantly away from the occupant and a belt opening angle between the portion of the seat belt adjacent to the retractor and the portion of the seat belt adjacent to the occupant is large, the friction between the seat belt and either of the thin parts can be reduced, and the seat belt can be smoothly drawn out. Thus, the handling operability of the seat belt can be improved. Moreover, in some cases, the seat belt barely comes into contact with either of the thin parts of the expanded portions and the peripheral portions thereof. In this case, the friction between the seat belt and either of the thin parts and that between the seat belt and the peripheral portions of the thin parts can be further reduced.
Moreover, a part of the belt guide anchor on the surface facing the exterior of the vehicle located on the back of the first thin part on the surface facing the interior of the vehicle is not made thin, and a part of the belt guide anchor on the surface facing the interior of the vehicle located on the back of the second thin part on the surface facing the exterior of the vehicle is not made thin. Thus, the strength of the belt guide anchor can be reliably maintained even when the thin parts are formed in the belt guide anchor.
Furthermore, since the width of a central guide opening of the belt insertion hole does not need to be increased, a warp or an offset (jamming) of the seat belt, which can be caused by an increase in the width of the central guide opening, can be avoided.
Furthermore, in the case where the thin parts are recessed portions, the thin parts can be simply formed by partially recessing the expanded portions. Thus, known belt guide anchors can be utilized, and an increase in cost can be regulated.
a) and 2(b) illustrate the belt guide anchor shown in
An embodiment of the present invention will now be described with reference to the drawings.
As shown in
a) and 2(b) illustrate the belt guide anchor in this embodiment.
As shown in
The belt insertion hole 5c is constituted by a linear central guide opening 5c1 guiding the seat belt 4 such that the seat belt 4 is slidable and curved relief openings 5c2 and 5c3 disposed at both ends of the central guide opening 5c1 so as to prevent the seat belt 4 from being twisted. The seat belt 4 drawn from the seat belt retractor 3 is fitted into the belt insertion hole 5c upward and forward of the vehicle, and folded at the belt insertion hole 5c downward and forward of the vehicle. The width of the central guide opening 5c1 is set to a value slightly larger than the maximum width set with consideration of the length required for folding the seat belt 4 at the belt insertion hole 5c (length between both side ends of the seat belt 4).
Moreover, the metallic plate 5a has an attachment hole 5d used for attaching the belt guide anchor 5 to the vehicle body. Furthermore, the resin portion 5b molded on the metallic plate 5a is constituted by expanded portions 5b1 and 5b2 projecting from the corresponding surfaces of the metallic plate 5a toward the interior and exterior, respectively, of the vehicle. Most parts of the belt guide anchor 5 in this embodiment including the belt insertion hole 5c and the attachment hole 5d are symmetrical or substantially symmetrical with respect to a vertical line passing through the center of the attachment hole 5d shown in
The structure of the belt guide anchor 5 in this embodiment differs from the basic structures of the typical known belt guide anchors in the following points. That is, as shown in
As shown in
The thin part 5e is not formed in a part 5b3 in the expanded portion 5b1 of the resin portion 5b on the surface of the belt guide anchor 5 facing the interior of the vehicle at a position adjoining a part of the central guide opening 5c1 facing the rear side of the vehicle (right side in
On the other hand, as shown in
The thin part 5f is not formed in a part 5b4 in the expanded portion 5b2 of the resin portion 5b on the surface of the belt guide anchor 5 facing the exterior of the vehicle at a lower position of a part of the central guide opening 5c1 facing the front side of the vehicle (right side in
According to the belt guide anchor 5 in this embodiment, the thin part 5e is formed in the expanded portion 5b1 of the resin portion 5b on the surface of the belt guide anchor 5 facing the interior of the vehicle at the lower position of the part of the central guide opening 5c1 facing the front side of the vehicle and the part of the relief opening 5c2 disposed in series with the part of the central guide opening 5c1 facing the front side of the vehicle when the belt guide anchor 5 is attached to the vehicle body. Thus, as shown in
Moreover, the thin part 5f is formed in the expanded portion 5b2 of the resin portion 5b on the surface of the belt guide anchor 5 facing the exterior of the vehicle at the lower position of the part of the central guide opening 5c1 facing the rear side of the vehicle and the part of the relief opening 5c3 disposed in series with the part of the central guide opening 5c1 facing the rear side of the vehicle when the belt guide anchor 5 is attached to the vehicle body. Thus, even when the portion of the seat belt 4 adjacent to the retractor to be passing through the belt insertion hole 5c is inclined at the maximum angle and extends upward and forward of the vehicle, the side end 4b of the portion of the seat belt 4 facing the rear side of the vehicle comes into light contact with the thin part 5f in the expanded portion 5b2 of the resin portion 5b and the peripheral portions of the thin part 5f.
With this structure, the friction between the seat belt 4 and the expanded portions 5b1 and 5b2 of the resin portion 5b can be reduced, and the occupant can smoothly draw the seat belt 4 out when he/she wears the seat belt. In this case, even when the seat belt 4 is drawn from a rear position of the vehicle significantly away from the occupant and a belt opening angle θ (shown in
In some cases, the seat belt 4 barely comes into contact with either of the thin parts 5e and 5f of the expanded portions 5b1 and 5b2, respectively, and the peripheral portions thereof In this case, the friction between the seat belt 4 and either of the thin parts and that between the seat belt 4 and the peripheral portions of the thin parts can be further reduced. Accordingly, the seat belt 4 can be drawn out more smoothly.
In contrast, the known belt guide anchor illustrated with the two-dot chain line shown in
Furthermore, the thin parts 5e and 5f can be simply formed by partially recessing the expanded portions 5b1 and 5b2, respectively, of the resin portion 5b. Thus, the known belt guide anchor 5 can be utilized, and an increase in cost can be regulated. In addition, since the width of the central guide opening 5c1 does not need to be increased, a warp or an offset (jamming) of the seat belt 4, which can be caused by an increase in the width of the central guide opening 5c1, can be avoided.
A belt guide anchor and a seat belt unit according to the present invention can be applied to seat belt units including belt guides that guide seat belts drawn from seat belt retractors to shoulders of occupants and fit the seat belts to the occupants so as to restrain the occupants using the seat belts guided by the belt guides.
Number | Date | Country | Kind |
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2007-105860 | Apr 2007 | JP | national |