Crew restraint device

Abstract

To provide an occupant restriction device which can efficiently restrict an occupant, and can prevent the generation of an excessive occupant restriction force.SOLUTION: A belt guide 5 for holding a seatbelt 2 in a state that a part of the seatbelt passes the vicinity of an upper part of a seatback 1b is arranged at the upper part of the seatback 1b of a seat 1 on which an occupant P is seated, and by arranging a belt holding release mechanism for releasing a holding state of the seatbelt 2 by the belt guide 5 after the activation of a pretensioner which is assembled to a retractor 3, an occupant restriction force at a collision initial stage is increased, and the occupant P can be efficiently restricted. In a collision latter stage, the seatbelt 2 passes an upper part of a position in which the seatbelt is held to the belt guide 5, and the generation of an excessive occupant restriction force can be thereby prevented.SELECTED DRAWING: Figure 4A

Description

Technical Field

[0001] This invention relates to an occupant restraint device including a seat belt for restraining an occupant sitting on a vehicle seat.

Background Art

[0002] Generally, vehicles such as automobiles are equipped with a three-point seat belt device including a seat belt for restraining an occupant and a retractor for retractably winding the seat belt as an occupant restraint device for preventing an occupant sitting on a seat from being thrown out of the seat and injured during a vehicle collision.

[0003] In recent years, in the above three-point seat belt device, in order to further reduce the risk of injury to the occupant during a collision, a pretensioner for winding the seat belt to eliminate slack in the seat belt when the vehicle is impacted is often incorporated into the retractor. In addition, a belt guide through which the seat belt is inserted is provided at the upper part of the seat back, and by holding the seat belt in a state where a part thereof passes near the upper side of the seat back, it has been proposed to be able to exhibit high occupant restraint performance during a vehicle collision or the like (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a three-point seat belt device including a belt guide as described above, compared with a conventional structure without a belt guide, the acting angle of the seat belt tension on the occupant (the angle formed by the seat belt bent near the occupant's chest) becomes smaller, and even if the seat belt tension is the same, the force for restraining the occupant becomes larger, so that the occupant can be efficiently restrained.

[0006] However, if the vehicle experiences an impact such as a collision and the pretensioner is activated, and the occupant's upper body tilts forward, the force restraining the occupant by the seat belt will increase further, potentially causing excessive compression of the occupant's chest by the seat belt.

[0007] Therefore, the objective of this invention is to provide a crew restraint device that can efficiently restrain crew members and prevent the generation of excessive crew restraint force. [Means for solving the problem]

[0008] To solve the above problems, the occupant restraint device of this invention comprises a seat belt for restraining an occupant seated on a seat having a seat portion and a seat back; a retractor for retractably winding the seat belt; a pretensioner incorporated into the retractor for winding the seat belt to eliminate slack when the vehicle is subjected to an impact; a belt guide provided on the upper part of the seat back for holding the seat belt in a position where a portion of it passes near the upper part of the seat back; and a belt holding release mechanism for releasing the seat belt from the belt guide after the pretensioner has been activated, wherein when the belt holding release mechanism is activated, the seat belt passes above the position where it was held by the belt guide (Configuration 1).

[0009] In the above configuration 1, the belt retention release mechanism can be configured to operate after a predetermined time has elapsed since the activation of the pretensioner (configuration 2).

[0010] Alternatively, the belt release mechanism may be configured to activate when a load exceeding a predetermined value is applied to the seat belt (Configuration 3).

[0011] Furthermore, when the above configuration 3 is adopted, the retractor is further equipped with a load limiter that, when the load acting on the seat belt exceeds a predetermined value, allows the seat belt to be extended so that the load remains below a predetermined value, and the belt retention release mechanism can be configured to operate when the load limiter is activated (configuration 4).

[0012] Furthermore, in any of the above configurations 1 to 4, the belt retention release mechanism can be configured to separate the belt guide from the seat back (configuration 5).

[0013] Furthermore, in any of the above configurations 1 to 5, a shoulder anchor is provided that is attached to the vehicle above the outside of the seat in the width direction and supports the seat belt, and the seat belt is pulled upward from the retractor, folded back by the shoulder anchor, then inserted into the belt guide and held so as to pass near the top of the seat back (configuration 6). [Effects of the Invention]

[0014] By adopting the above configuration, this invention can efficiently restrain occupants during vehicle collisions and other incidents, while preventing the generation of excessive occupant restraint forces, thereby preventing excessive loads from being placed on the occupants. [Brief explanation of the drawing]

[0015] [Figure 1] This diagram illustrates the schematic configuration of a crew restraint device according to an embodiment of the present invention. [Figure 2A] Diagram illustrating the occupant restraint force of the occupant restraint device immediately after a collision (Figure 1) [Figure 2B] Diagram illustrating the occupant restraint force of the occupant restraint device in the comparative example immediately after the collision. [Figure 3A] Figure 1 is an explanatory diagram of the initial collision state of the occupant restraint system. [Figure 3B] Diagram illustrating the initial collision state of the occupant restraint device in the comparative example. [Figure 4A] Figure 1 is an explanatory diagram of the occupant restraint system in the late stages of a collision. [Figure 4B] Explanatory drawing of the late-stage collision state of the occupant restraint device of the comparative example

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of this invention will be described based on the drawings. As shown in FIG. 1, the occupant restraint device of this embodiment includes a seat belt (webbing) 2 that restrains an occupant P sitting on a seat 1 having a seat portion 1a and a seat back 1b, an anchor (not shown) fixed to the outside in the width direction of the seat 1 to which one end of the seat belt 2 is connected, a retractor 3 that retracts the other end of the seat belt 2 in a drawable manner, and a D-ring-shaped shoulder anchor 4 that is attached to the vehicle above the outside in the width direction of the seat 1 and supports the seat belt 2. It is a three-point seat belt device.

[0017] The seat belt 2 is drawn upward from the retractor 3 and folded back by the shoulder anchor 4, and then is inserted through a belt guide 5 provided at the upper part on the outside in the width direction of the seat back 1b. A tongue plate (not shown) attached to the seat belt 2 fits into a buckle 6 provided on the inside in the width direction of the seat portion 1a of the seat 1, so that it extends from the shoulder of one side (outside in the width direction of the seat 1) of the occupant P to the waist of the other side (inside in the width direction of the seat 1). It is configured to restrain the occupant P at a portion extending toward the waist and a portion extending horizontally along the waist of the occupant P.

[0018] The retractor 3 is attached to the vehicle below the shoulder anchor 4, and a pretensioner and a load limiter (both not shown) are incorporated. The pretensioner winds up the seat belt 2 so as to eliminate the slack of the seat belt 2 when the vehicle is impacted. Also, when the load acting on the seat belt 2 exceeds a predetermined value after the pretensioner operates, the load limiter allows the seat belt 2 to be pulled out so that the load stays below the predetermined value.

[0019] The belt guide 5 is for holding the seat belt 2 in a state where a part of it passes near the upper part of the seat back 1b. However, as will be described later, it is designed to separate from the seat back 1b under certain conditions. That is, in this embodiment, a belt holding release mechanism is provided to separate the belt guide 5 from the seat back 1b and release the holding state of the seat belt 2 by the belt guide 5.

[0020] The occupant restraint device of this embodiment has the above configuration. Next, the operation during a vehicle collision will be described based on FIGS. 2A to 4B. In the description of the operation, the occupant restraint device of the above configuration will be used as an example (FIGS. 2A, 3A, 4A), and the occupant restraint device of the conventional structure will be used as a comparative example (FIGS. 2B, 3B, 4B), and the differences in the operations of the two will be described. The structural difference between the example and the comparative example is only the presence or absence of the above belt guide 5.

[0021] When the vehicle collides, first, as shown in FIGS. 2A and 2B, in both the example (FIG. 2A) and the comparative example (FIG. 2B), a signal is sent from a sensor (not shown) to the retractor 3 and the pretensioner is activated, and the seat belt 2 is wound up by the retractor 3 so that there is no slack. As a result, the occupant P is pressed against the seat back 1b.

[0022] At this time, in the example, since the seat belt 2 is held by the belt guide 5 in a state where it passes near the upper part of the seat back 1b, compared with the comparative example where the seat belt 2 passes more above, the acting angle of the tension of the seat belt 2 with respect to the occupant P (the angle formed by the seat belt 2 bent near the chest of the occupant P) is smaller. Even if the tension of the seat belt 2 is the same, the resultant force of the tension, that is, the force (occupant restraint force) F that restrains the vicinity of the chest of the occupant P, becomes larger.

[0023] Therefore, at the initial stage of the collision, as shown in FIGS. 3A and 3B, in the example (FIG. 3A), the forward inclination of the upper body of the occupant P receiving the inertial force is less than that in the comparative example (FIG. 3B), and the tip position a1 of the head of the occupant P in the example remains on the rear side compared to the tip position b1 of the head of the occupant P in the comparative example.

[0024] As occupant P moves forward and tilts their upper body during the initial stages of the collision, the load acting on the seat belt 2 increases. When this load exceeds a predetermined value, the load limiter of the retractor 3 is activated. The period after this load limiter is activated is referred to as the late stage of the collision.

[0025] In the later stages of the collision, as shown in Figure 4A, when the load limiter is activated, the belt release mechanism is activated and the belt guide 5 separates from the seat back 1b, releasing the seat belt 2 from the belt guide 5, and the seat belt 2 moves above the position where it was held by the belt guide 5.

[0026] As a result, in the later stages of the collision, as shown in Figures 4A and 4B, the angle of action of the seat belt 2 tension on the occupant P in the embodiment (Figure 4A) is about the same as in the comparative example (Figure 4B). In both the embodiment and the comparative example, the forward tilt of the occupant P's upper body increases as the seat belt 2 is pulled out from the retractor 3 due to the action of the load limiter, but the position a2 of the tip of the occupant P's head in the embodiment remains further back than the position b2 of the tip of the occupant P's head in the comparative example. The difference in the head tip positions (b2-a2) is almost the same as the difference in the head tip positions at the beginning of the collision (b1-a1).

[0027] In other words, in the occupant restraint device of the embodiment, the occupant restraint force in the later stages of the collision is the same as in the comparative example, but the occupant restraint force in the initial stages of the collision is greater than in the comparative example. Therefore, the tilt of the occupant P's upper body (displacement of the upper body relative to the vehicle) can be suppressed more effectively than in the comparative example. Consequently, contact of the occupant P's head with interior components (such as the dashboard) can be prevented more reliably than in the comparative example.

[0028] Furthermore, in the later stages of a collision when the load acting on the seat belt 2 increases, the belt guide 5, which enhances occupant restraint performance, separates from the seat back 1b, thus preventing the generation of excessive occupant restraint force. Specifically, the force restraining the chest area of ​​occupant P becomes about the same as in the comparative example, so occupant P's chest is not excessively compressed by the seat belt 2, and the load on occupant P can be kept at the same level as in the comparative example.

[0029] Here, the belt retention release mechanism can consist of, for example, a locking device that locks the belt guide 5 in a fixed position on the seat back 1b, and an actuator that receives a signal from the airbag control device and releases the locking device. When the actuator releases the lock on the belt guide 5, the tension of the seat belt 2 pulls up the belt guide 5, separating it from the seat back 1b, and the seat belt 2 is also released from its holding state.

[0030] Furthermore, the belt retention release mechanism is not limited to one that separates the belt guide from the seat back, as in the embodiment; it may also be configured to allow the seat belt to detach from the belt guide. For example, a configuration can be adopted in which the belt guide breaks when a load exceeding a predetermined value is applied to the seat belt.

[0031] In the embodiment described above, the belt release mechanism is activated when the load limiter is activated. However, the timing of the belt release mechanism's activation can be set to an appropriate timing after the pretensioner is activated. For example, it may be set to activate after a predetermined time (approximately 0.05 to 0.07 seconds) has elapsed since the pretensioner was activated, or when a load exceeding a predetermined value is applied to the seat belt.

[0032] Furthermore, in the above-described embodiment, the occupant restraint force at the initial stage of the collision was increased compared to the comparative example to reduce the final displacement of the occupant's upper body. However, it is also conceivable that the set value of the seat belt load at which the load limiter activates could be lowered by an amount equivalent to the effect of increasing the occupant restraint force at the initial stage of the collision, thereby reducing the load on the occupant to a level similar to that of the comparative example while keeping the displacement of the occupant's upper body to a similar level.

[0033] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. Accordingly, the scope of this invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0034] 1 sheet 1a Seat 1b Seat back 2 Seat belts 3 Retractors 4 Shoulder Anka 5 Belt Guide 6 buckles P Crew

Claims

1. A seat belt that restrains an occupant seated in a seat having a seat cushion and a seat back, A retractor that retracts the aforementioned seat belt so that it can be pulled out, A pretensioner incorporated into the retractor, which retracts the seat belt to eliminate slack in the seat belt when the vehicle is subjected to an impact, A belt guide is provided at the top of the seat back and holds the seat belt such that a portion of it passes near the top of the seat back, A belt release mechanism that releases the seat belt from being held by the belt guide after the pretensioner has been activated, Equipped with, The belt release mechanism is activated when a load exceeding a predetermined value is applied to the seat belt, and when the belt release mechanism is activated, the seat belt moves above the position in which it was held by the belt guide.

2. The retractor further incorporates a load limiter that, when the load acting on the seat belt exceeds a predetermined value, allows the seat belt to be extended so that the load remains below a predetermined value. The occupant restraint device according to claim 1, wherein the belt retention release mechanism is activated when the load limiter is activated.

3. The occupant restraint device according to claim 1, wherein the belt retention release mechanism separates the belt guide from the seat back.

4. The seat is mounted above the outer side in the width direction of the seat and is equipped with a shoulder anchor that supports the seat belt, The occupant restraint device according to any one of claims 1 to 3, wherein the seat belt is pulled upward from the retractor, folded back at the shoulder anchor, and then inserted into the belt guide and held so as to pass near the upper part of the seat back.

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