JP3329511B2 - Inflatable seat belt device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inflatable seatbelt device, and more particularly to a webbing of a seatbelt device mounted so as to restrain an occupant, wherein a part of the webbing is formed of a bag-shaped inflatable structure. The present invention relates to an inflatable seatbelt device which is shaped like a belt when normally worn and which expands into a predetermined shape while ensuring safety against high-temperature gas ejected from gas generating means connected at the time of a vehicle collision or the like.

[0002]

2. Description of the Related Art At present, a seatbelt device is an indispensable device in an automobile or the like as a device for restraining a sudden movement of an occupant due to acceleration or impact force generated at the time of collision and for ensuring the occupant's body. This type of seat belt device includes a normal webbing (hereinafter, a woven belt made of a normal fiber material having a width of about 50 mm as defined in Japanese Industrial Standards is referred to as a webbing) and this webbing. A retractor (hereinafter referred to as ELR :) which is wound by a spring force and pulled inside, and locks the drawer of the webbing to restrain an occupant only when an impact is applied.
Emergency Locking Retractor. ) And a buckle device, a tongue, an anchor, and the like in which the webbing is installed at an appropriate position to fit the occupant so as to fit the occupant's body.

Conventionally, in the above-mentioned seat belt device, at the time of a collision, the webbing is pulled out by the operation of the ELR so that the movement of the occupant is restricted. Recently, in order to improve the occupant restraint performance, a part of the webbing is formed into a bag shape with woven cloth, and at the time of normal mounting, the bag-shaped portion is folded into a fan shape etc. Or the folded portion is shaped like a band by a fastener such as a fastener, so that the bag-shaped portion is inflated and deployed by the gas ejected from the gas generating means connected to the webbing when an impact is applied. There has also been proposed a seat belt apparatus (see U.S. Pat. No. 3,865,398).

According to a seat belt device having an inflatable bag-shaped portion of this kind (hereinafter referred to as an inflatable seat belt device), a load acting on an occupant can be dispersed over a wider area than conventional webbing. Therefore, the load received by the occupant can be reduced, and safety can be further improved.

[0005] The effect of the inflatable seat belt device can be expected also in a rear seat. That is, in order to install the airbag device for the occupant of the rear seat, the airbag device is usually provided at the rear of the front seat. In order to properly operate the airbag device for the rear seat and to effectively restrain and protect the occupant, the front seat structure needs to have high rigidity. For this reason, if the airbag device is provided, it is difficult to provide a reclining function having a movable portion to the front seat. Therefore, the inflatable seatbelt device which can be independently mounted on the seat and is free from the above-mentioned restrictions is very effective for the rear seat.

As described above, in the inflatable seat belt device, when a collision occurs, the above-mentioned gas generating means is activated by an operation signal from a detection unit such as an acceleration sensor which detects the collision, and almost instantaneously. The inflatable bag-like portion can be inflated and deployed in a predetermined shape. As the gas generating means, it is necessary to instantaneously inject gas into the inflated portion as in the case of the airbag device, so that a type of supplying compressed inert gas or compressed air filled in a pressure vessel such as a cylinder is used. The device is being used. As the inert gas, nitrogen, carbon dioxide, or the like is used. In the case of compressed air, a small compressor is often mounted together.

In this case, the volume of the inflatable body of the inflatable seat belt device is 1/6 to 7 as compared with the airbag device.
The airbag device does not need to be as large as an airbag device. However, even if it is small, it is necessary to additionally provide a device for surely attaching and detaching the cylinder, a gas leakage prevention device, and the like, and it is necessary to periodically check the gas filling pressure in the cylinder. Therefore, in recent airbag devices, a device that instantaneously generates a gas using a rapid combustion reaction of a filling compound as a gas generating means (hereinafter, referred to as an inflator) has been dominant.

As a typical gas generation mechanism of this type of inflator, first, an operation signal from an acceleration sensor obtained at the time of a collision is caused to act on an electric ignition device as a trigger, and an ignition agent is used by an electric ignition device (igniter). It ignites and burns the propellant, which causes rapid gas evolution. Sodium nitride (sodium azide: NaN ₃ ) is well known as a propellant,
The combustion produces nitrogen gas. In addition, in the case of a conventional inflatable seatbelt device in which a thick woven fabric is folded, a silicone coating is applied to the inner surface of the woven fabric in order to increase the airtightness of the expanding bag-like portion, and further, to reduce the temperature of the introduced gas. In addition, a simple cooling filter is provided in the inflator so that high-temperature gas from the inflator is directly introduced into the bag.

By the way, the applicant has already described the inflatable seat belt device in which the bag-like portion is constituted by a knitted fabric structure and an inflatable body of a rubber tube is inserted therein, and the bag-like portion is formed by weft (weft). The invention discloses an invention in which a woven fabric structure having a structure in which the rubber tube is sufficiently elongated and an inflatable body of a rubber tube is inserted therein. According to these inventions, the seat belt device is retained in a relatively thin band shape compared to the folded type of the woven fabric structure made of thick fabric during normal wearing, and the bag-shaped portion is used in an emergency. The effect of being able to inflate and deploy reliably and quickly is obtained.

FIG. 12A schematically shows an example of an inflatable seat belt device in which a part of a shoulder belt has a tubular knitted fabric structure and a bag-shaped rubber tube is inserted therein. . In the figure, reference numeral 51 denotes a tongue. The tongue 51 has a gas flow hole 54 serving as a gas introduction port to a rubber tube 53 in a belt 52 therein. When the tongue 51 is engaged with the buckle device 55 in order to fix the belt end portion 52a to the vehicle body, the gas flow hole 54 is used for gas injection of the gas generating means (inflator) 56 connected to the buckle device 55. It communicates with the outlet 56a.

FIG. 12B shows a reaction gas generated by burning the propellant in the inflator 56 having the above-described structure, and this gas is introduced into the rubber tube 53 of the belt 52 through the gas flow holes 54. Then, the state in which the belt 52 is expanded and deployed in a predetermined shape is schematically shown. As shown in the figure, when the gas is rapidly introduced into the rubber tube 53 and expanded, the shape of the entire belt is adjusted by the bag-like knitted fabric structure 57 that wraps the tube, and becomes a long and thin spindle shape.
In this way, the area of the belt portion in contact with the occupant's chest or the like increases, so that the impact applied to the human body is reduced. In addition, the length of the belt in the longitudinal direction is shortened by ΔL by the radial expansion of the bag-shaped inflatable portion. As a result, a pretension effect for more effectively protecting the occupant can be expected.

[0012]

In this type of inflatable seat belt device, gas ejected from the inflator is introduced into the tube at a high temperature and a high pressure simultaneously with combustion. FIG. 13 is a temperature distribution diagram schematically showing the result of measuring the temperature distribution in the tube at this time. In addition, in order to show the position of the same figure, the belt portion in the expanded state is also shown below the graph. At this time, the temperature in the tube becomes highest near the gas inlet of the tongue portion as shown in FIG. Further, as indicated by a broken line in the tube, the maximum temperature is shown at each point along with the gas introduction in the longitudinal direction L, and it is considered that the maximum temperature position moves toward the tube tip in a very short time. The solid line shows the maximum temperature envelope at each point. As described above, the gas generated by the combustion reaction in the inflator has a very high temperature, but has a certain temperature gradient in the longitudinal direction. Perform functions. Therefore,
The tube into which the high-temperature gas is introduced is made of heat-resistant silicone rubber so as to withstand the high temperature state inside.

However, the combustion reaction of the propellant in the inflator generates a large amount of scum. This slag is mainly fine carbon powder, and the slag is ejected into the tube together with the reaction gas. Since the slag itself is hot, it spouts out into the tube, deteriorating the rubber surface of the tube when it collides with the inner surface of the tube. .

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a highly safe inflatable seat belt device in which a tube at an expanded portion of the belt is not exposed to high-temperature gas and is not damaged during expansion and deployment. Is to provide.

[0015]

Means for Solving the Problems In order to achieve the above-mentioned object, according to the present invention, when normally mounted, a gas is generated by a gas generating means which operates in response to an operation signal from a collision detection unit while being kept in a band shape. Structure that has a bag-shaped portion that introduces the gas into the interior and expands and deploys in a substantially spindle shape, a webbing provided at least over a range where the expandable structure contacts an occupant, and an end of the expandable structure A tongue having a gas introduction passage from the gas generating means fixed to the inside, and a buckle device to which the tongue is removably fitted and locked, in the inflatable seatbelt device, the inflatable structure, An elastic inflatable body was inserted into the bag-like portion, and the elastic inflatable body was ejected from the gas generating means .
Gas is introduced and expanded and deployed through a filter extending into the elastic expansion body .

In this case, it is preferable that the filter is a cylindrical bag filter inserted into the elastic inflatable body. Preferably, the bag filter is made of a woven fabric of heat-resistant fiber. Further, it is preferable that the elastic expansion body is a silicone rubber tube.

[0017]

According to the present invention, an elastic inflatable body is inserted into a bag-like portion in the inflatable structure, and the elastic inflatable body is inserted into the gas generating section.
The gas ejected from the raw means extends into the elastic inflatable body.
Since the gas is introduced through the filter and expanded and deployed, the temperature of the high-temperature and high-pressure gas generated by the combustion reaction in the gas generating means can be lowered, and the high-temperature scum can be captured by the filter. It is possible to prevent the slag discharged together with the gas introduced into the elastic expander from adhering to the inner surface of the elastic expander and preventing the elastic expander from melting and breaking.

Further, by using a cylindrical bag filter as the filter, the temperature can be reduced in the longitudinal direction of the elastic inflatable body, and the slag can be trapped in a wide area. Since there is no elastic expansion body, the elastic expansion body can reliably perform the expansion and deployment operation.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the inflatable seat belt device according to the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a schematic perspective view showing the entire configuration of the inflatable seat belt device 1. FIG. 1 shows an inflatable seat belt device 1 incorporated in a front seat.
Are shown so as to clarify the relationship between the components.

In the figure, reference numeral 2 indicates a shoulder belt,
The shoulder belt 2 has a tongue 3 fixed to one end 2a, and is engaged and fixed via a tongue 3 to a buckle device 4 fixed at a predetermined position near the floor between the left and right front seats, and the other end 2b is fixed to the shoulder belt 2. It is guided downward by a slip guide 5 of a pillar anchor attached to a pillar (intermediate pillar) (not shown) so as to be able to adjust its position in the vertical direction, and is wound around an ELR 6 installed near the floor in the pillar. Have been. The lap belt (waist belt) 7 has an end 7a fixed to an anchor plate 8 fixed to a base portion of the tongue 3, and an other end 7b provided near the door-side floor over the seat seat surface. It is wound around.

In the following, details of each structure of the shoulder belt, the tongue rotation, and the buckle device will be described. As shown in FIG. 1, one end 2b of the shoulder belt 2 is wound and housed in the ELR 6, and one shoulder webbing 10 having a tongue 3 connected to the other end 2a is formed as a passing material. In the present embodiment, the webbing 10 is made of densely woven polyester processing yarn by twilling, plain weaving, or the like, and has a width of about 50 mm and a thickness of 1.6.
Although a belt-shaped belt of about mm is used, the webbing 10 is equivalent to that used in a normal seat belt device. Further, a portion from the abdomen to the right shoulder, which is in contact with the occupant's body, is formed with a slightly thick portion covered with a tubular cloth cover 20. Various bag-like structures as shown in FIG. 2 are accommodated in the thick portion in a multilayer manner.

In FIG. 2, reference numeral 10a denotes a state in which the webbing 10 is located inside the cover 20. Hereinafter, the belt of this portion is referred to as an inner belt 21 from the functional distinction, and the belt of the portion exposed to the outside and wound around the ELR 6 is referred to as a webbing 10, and different reference numerals 10 and 21 are given to them. explain. As shown in FIG. 2, the inner belt 21 is inserted into a thin film tube 22 made of silicone rubber in a flat state. The silicone rubber tube 22 has a tubular shape, and its end 22a is fixed to a predetermined position of the inner belt 21 so as to maintain airtightness as shown in FIG. For this reason, when gas is introduced into the tube 22, it expands into an elongated tubular shape.

The tube 22 is accommodated in a tubular flat knitted fabric 23 knitted to a slightly larger size. In this embodiment, the knitted fabric 23 is constituted by a circular knit using polyester processed yarn (1500d), and the knitted fabric 23 of the circular knit is in the belt longitudinal direction (the warp direction of the knitted fabric: the warp direction). It has the property of being easily stretched in a direction (the weft direction of the knitted fabric: the weft direction) in which the circumference of the cylindrical shape becomes large.

Further, the above-mentioned cloth cover 20 is attached so as to cover the entire tubular knitted cloth 23, and as shown in FIG. 6A, the knitted cloth 23 and the cover 20 are stitched to the inner belt 21 by pattern sewing. It is sewn firmly. In addition, since the cover 20 is a portion that the occupant directly grasps and is in direct contact with the occupant's clothes, the material thereof is preferably a wrinkle-resistant and comfortable fabric, and in this embodiment, the polyester yarn is used. Warp knitted tricots are used.

As described above, this thick portion has the inflatable tube 22 with the inner belt 21 as a core, one end of which is connected to the gas generating means via the tongue 3 and introduced at the time of collision. The gas expands and deploys, and the movement of the occupant can be effectively restrained. Less than,
In the present specification, when referring to the entire inflated portion, it is referred to as an “expanded structure”.

The components of the expansion structure include the following modifications in addition to the above-described embodiment. First, as the tube 22, a rubber material which can be made relatively thin, has heat resistance since the inside is filled with a high-temperature gas, and has sufficient elasticity against sudden expansion is suitable. For example, in addition to various thermoplastic elastomers having remarkable rubber elasticity, urethane rubber, fluorine rubber, rubber / rubber blends and the like can be used.

In the above-described embodiment of the knitted fabric 23, a round knit of weft knitting (weft knitting) without a seam for forming a tubular shape is used. Various types of knitting such as rib knitting, pearl knitting, and interlock (double-sided knitting) can be used. At this time, by changing the density of the course (C) of the weft knitting loop in the vertical direction, it is possible to change the elongation of the knitted fabric 23 in the weft direction. Flat knitting produces a flat knitted fabric, but two slender knitted fabrics are overlapped and their ends are sewn together to form a tubular shape, or one end of a single knitted fabric is sewn in a loop. Is also good. Also,
As the cloth used for the cover 20, plain woven cloth using nylon yarn or polyester yarn can be used. In addition, other than the cloth as in the embodiment and the modification,
As long as the requirements such as touch, strength, and durability are satisfied, a resin film, artificial leather, or another material can be used as the cover.

FIG. 3 is an exploded perspective view showing a state during expansion and deployment so that the inside of the expansion structure shown in FIG. 2 can be seen. As shown in the figure, when the tube 22 expands due to the introduced gas, the knitted fabric 23 made of a circular knit expands in the weft direction and expands in a tubular shape. Then, at a stage where a predetermined internal pressure is applied, a part of the sewing thread at a portion where the cloth of the cover 20 is sewn is broken. Then, the seam 20a of the cover 20 spreads so as to open the mouth, and the tube 22 wrapped in the circular knit knitted fabric 23 expands into a spindle shape so as to protrude from the portion. On the other hand, in the predetermined range of the expansion structure 25 on the pillar anchor side and the predetermined range on the tongue 3 side, the seam 2
0b is firmly sewn, the expansion of the tube 22 is restrained by the cover 20 portion 20c, and the cover portion 2c
0c expands only into a thin cylindrical shape (having a diameter of about 3.6 cm in this embodiment). In addition, the expansion structure 25
Is expanded and developed into a spindle shape, so that the length of the belt in the longitudinal direction is reduced. At this time, since the knitted fabric 23 of the circular knit of the expansion structure 25 bears the tension in the longitudinal direction of the belt, no tension acts on the inner belt 21 and the inner belt 21 is in a loosened state.

Next, details of the structure of the engagement between the inflatable structure 25 and the tongue 3 having the gas inlet in this embodiment and the configuration of the bag filter will be described with reference to FIGS. FIG. 4 is a perspective view showing a joint between the tongue 3 and the expansion structure 25. 4 and 10, the end 25a of the expansion structure 25 is fixed so as to cover a metal end fitting 31 having a flat rectangular cross section, and is firmly fixed by a caulking fitting 32 so as to further cover the outer periphery thereof. As a result, the expansion structure 25 is not easily detached from the end fitting 31.

A tongue pipe 33 inserted and engaged with the buckle body of the buckle device 4 (not shown) is fixed to the tip of the end fitting 31. The tongue pipe 33 has a gas flow hole 34 formed therein.
A gas from an inflator (not shown) is introduced into the expansion structure 25 through the inside of the end piece 4 and the end fitting 31. As described above, the tongue 3 according to the present embodiment is integrally formed by combining the end fitting 31, the caulking fitting 32, and the tongue pipe 33. A lap belt anchor plate 8 is fitted to the root of the tongue pipe 33 so that the end 7a of the lap belt 7 made of normal webbing can be fixed.

FIG. 5 is a longitudinal sectional view showing an arrangement state of each component of the expansion structure 25. As shown in the figure, each part (the inner belt 21, the bag filter 26, the tube 22, the knitted fabric 23, and the cover 20) of the inflatable structure 25 comes into close contact with the outer peripheral portion of the end fitting 31 covered with the rubber coating 31a. As described above, a crimping fitting 32 whose inner surface is covered with a rubber coating 32a is fitted to the outer peripheral portion thereof. (The caulking fitting 32 is shown in a separated state in FIG. 5). With such a configuration, the expansion structure 25 is kept airtight at its end 25a, and the high-pressure reactant gas is supplied. Even if it is suddenly introduced into the expansion structure 25, the end fitting 31 does not come off or break.

Here, the configuration of the bag filter 26 will be described in detail. The bag filter 26 is a highly permeable fabric filter sewn in an envelope shape having a width substantially equal to that of the inner belt 21 and a closed cylinder end, inserted into the tube 22, and one end of which is fixed to the tongue 3. . Further, a skirt 27 having a length of about 1/3 of the length of the bag filter 26 is inserted therein. The skirt portion 27 has a tubular shape with an open tubular tip, and in the present embodiment, a cloth made of the same material as the bag filter 26 is used.

The bag filter 26 and the skirt 27 of this embodiment use heat-resistant fibers. Aramid fiber is an example of this heat resistant fiber. This aramid fiber is a fiber having high strength and high elasticity known under the trade name Kevlar (registered trademark), but also has excellent heat resistance and flame resistance, has a carbonization start temperature of about 500 ° C., and can be used at high temperatures. Does not self-melt or self-burn. Although Kevlar used in this example is a para-bonded aramid fiber, it is naturally possible to use a meta-bonded aramid fiber from the viewpoint of heat resistance. However, it is also possible to configure a filter.

The bag filter 26 is inflated by the gas ejected from the inflator, and has air permeability, so that it is possible to attach a certain size or more of slag to its inner surface. The gas that has passed through the bag filter 26 inflates the tube. At this time, the gas temperature is sufficiently reduced, so that the effect as a filter and the effect as a diffuser are exhibited. In addition, the skirt 27 is arranged so that the vicinity of the tongue is doubled in consideration of the temperature distribution shown in FIG.

As described above, aramid fibers are used in the present embodiment. However, as fibers other than aramid fibers, carbon fibers, alumina fibers, silicon carbide fibers, glass fibers, and the like can be used as fibers having high heat resistance. Among them, the carbon fiber is obtained by calcining and carbonizing the organic fiber, so that the heat resistance is excellent, and when used as a diffuser having no strength burden as in the present invention, heat resistance up to about 2000 ° C. can be expected. . Alumina fiber, which is an oxide-based inorganic material, also has extremely high heat resistance and is easy to use as a woven fabric.

FIG. 6 (a) shows the state of the terminal processing on the slip guide 5 side of the inflatable structure 25 and the webbing 10 (called the inner belt 21 when it is inside the inflatable structure 25 as described above). It is sectional drawing. Here, the configuration will be described again. The end of the circular knitted knitted fabric 23 is integrally bonded together with the end 20d of the cover 20 with an adhesive, and is firmly sewn to the webbing 10 by pattern sewing. Is done. Then, an end 22a of a tube 22 made of silicone rubber is welded or bonded to the inner belt 21 in the knitted fabric 23 inside the pattern sewing portion. Further, the tube tip of the bag filter 26 extends inside the tube 22.

FIG. 6 (b) shows a modification of FIG. 6 (a), in which the end of the circular knit is integrally bonded together with the end 20d of the cover 20 as in FIG. 6 (a). The end of a tube 22 is welded or adhered to an inner belt 21 at an end 22a to which the tube 22 is fixed. The tube 22 accommodates only a tubular bag filter 26 that performs the same function as described above.

In this modification, the expansion structure 25 itself functions as "webbing" in the case of a slight collision or the like in which the gas generating means does not operate. That is, since the inflatable structure 25 hardly extends in the longitudinal direction due to the extensibility of the used knitted fabric 23, it can bear the acting tension of the belt similarly to the ordinary webbing 10, and can appropriately restrain the occupant. It is. Further, at the time of a collision, the occupant can be restrained and protected by a wide area of the inflatable structure since the inflatable structure 25 expands in an appropriate shape as in the embodiment shown in FIG.

7 to 9 are explanatory views showing an embodiment of the buckle device. This buckle device 4 is a tongue pipe 3
3 and has a built-in gas generating means, and serves to introduce the gas ejected from the gas generating means into the expansion structure 25 through the gas flow holes 34 in the tongue pipe 33. The connection between the buckle device 4 and the tongue 3 is made such that a portion protrudes from the annular groove 33b formed on the outer peripheral surface of the tip portion 33a of the tongue pipe 33 and the inner surface of the connection hole 44a formed on the buckle device 4. This is performed by locking with a metal ball 47 buried in the substrate.

In FIG. 7, reference numeral 41 denotes a housing, and the buckle device 4 is fixed near the floor of a vehicle body (not shown) by a flange plate 42 partially fixed to the housing 41. ing. In the housing 41, a gas generator 43 as a gas generating means is fixed to the flange plate 42, and a buckle body 44 also serving as a gas distribution pipe is firmly connected to the gas generator 43.

FIG. 3 shows a state where the tongue pipe 33 is engaged. As shown, when the tongue pipe 33 is fitted and locked in the connection hole 44a of the buckle body 44, the tongue pipe release ring 45 is pressed by the tongue pipe tip 33a against the urging force of the spring 46 and is pushed in the direction of arrow A. . On the other hand, the buckle body 44
Tapered holes 44b are formed at predetermined intervals at the tip of the outer peripheral surface of the buckle body 44 from the outer peripheral surface side of the buckle body 44 so that each tapered hole 44b projects partly into the inner peripheral surface of the connection hole 44a. A metal ball 47 is loosely fitted. This metal ball 47
When the tongue pipe 33 is locked, it is pressed from the outer peripheral surface side of the buckle body 44 by a detachable operation ring 49 urged in the direction of arrow B by a spring 48, thereby
7 protrudes into an annular groove 33b formed on the outer peripheral surface of the tongue pipe 33, and the annular groove 33b of the tongue pipe 33
, The tongue pipe 33 is fixedly locked in the connection hole 44a.

On the other hand, to release the tongue pipe 33, a press button 50 provided on a part of the housing may be pressed in the direction of arrow C as shown in FIG. The press button 50 is a non-encircling type operation button, and as shown in FIG. 9, the pressing surface 50a faces the upper front position of the housing, so that the occupant can operate with one touch.

Hereinafter, a mechanism for simply releasing the tongue 3 from the buckle device 4 will be described. When the press button 50 is pressed in the direction of arrow C as shown in FIG. 8, the detachable operation ring 49 is operated by the operation arm 50b protruding from the press button.
Slides in the direction of the arrow C against the urging force of the spring 48, the pressing from the attachment / detachment operation ring 49 is stopped, the metal ball 47 becomes free, and the annular groove 33b of the tongue pipe 33 of the metal ball 47 is used. Is released. As a result, the tongue pipe release ring 45 in the buckle body 44 is urged in the direction of arrow D by the spring 46, and the tongue pipe 33 is moved from the buckle body 44 to the direction of arrow D.
The tongue 3 is released from the buckle device 4.

FIG. 10 is an explanatory view showing a modification of the bag filter 26 described above. In the above-described embodiment, as shown in FIG. 5, the skirt 27 is provided inside the bag filter 26 in order to increase the heat resistance in the vicinity of the tongue 3 where the jet gas temperature is high. If the belt has a double structure and is thick, the feel and wearing feeling of the belt may be deteriorated. Therefore, the modified example shown in FIG. 10 is configured by one bag filter. The bag filter 26 shown in FIG. 3A shows an example in which woven fabrics of different fabric thicknesses made of aramid fibers are used, and the heat resistance is changed in the longitudinal direction. In the vicinity of the tongue, a diffuser is used as a diffuser to reduce the temperature. Using thick cloth 26A,
A thin cloth 26 </ b> B that mainly obtains a filter effect is used for the tube tip. In addition, it is also possible to perform sewing by combining different types of heat resistant fibers. That is, a fiber having higher heat resistance may be used on the tongue side, and a thin aramid fiber woven fabric may be used on the cylinder tip side.

FIG. 5B shows an example in which a metal film coating such as aluminum is applied to a region corresponding to the skirt position on the inner surface of the bag filter 26. As shown in the figure, the air permeability is lost in the coating part,
Since the heat shielding property at the tongue portion is improved, the temperature in the tube is averaged, and the maximum temperature near the tongue can be reduced.

FIG. 1 shows the coating range.
It is preferable to set in consideration of the range of the gas flow as shown in FIG. That is, the shoulder belt (tube 2 in the figure)
2, only the inner belt 21 and the bag filter 26 are partially shown. ) Is mounted with a large curve near the tongue so that it fits the occupant D's body shape. In this state, when gas is ejected from an inflator (not shown), the heat flow intensively hits the elbow-shaped portion 26a of the bag filter 26 directly. Therefore, the temperature of the elbow-like portion 26a partially rises to a considerable temperature. In the present embodiment, since the bag filter 26 itself is employed as not directly receiving radiant heat, it is necessary to cope with such partial and continuous heating. Therefore, it is preferable to apply the above-mentioned coating to the elbow-shaped portion 26a, or to take measures to overlap two woven fabrics in this portion.

[0047]

As is apparent from the above description, according to the present invention, the conventional webbing exhibits the restraint performance provided by the conventional webbing at the time of normal mounting, and safely removes the hot gas generated from the inflator at the time of collision or the like. Can be introduced into the inflatable structure, and the inflatable structure can be inflated to an appropriate shape, so that even when using gas generated by combustion, high safety is exhibited, and the occupant is effectively restrained and protected by the inflatable structure. It has the effect that it can be done.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an inflatable seat belt device according to a first invention.

FIG. 2 is a partially exploded perspective view schematically illustrating the inside of the inflatable structure when the inflatable seat belt device shown in FIG.

3 is a partially exploded perspective view schematically showing the inside of an inflatable structure when the inflatable seatbelt device shown in FIG. 2 is inflated and deployed.

FIG. 4 is a perspective view showing a structure in which a tongue and an end of an expansion structure are joined together.

FIG. 5 is a longitudinal sectional view showing an arrangement state of each component of the expansion structure.

FIG. 6 is a partial longitudinal sectional view showing the structure of the terminal treatment on the slip guide side of the expansion structure.

FIG. 7 is a plan sectional view showing a schematic structure of a locking portion of the buckle device.

FIG. 8 is a longitudinal sectional view showing a tongue releasing operation by a press button of the buckle device.

FIG. 9 is an end view of the buckle device as viewed from the front.

FIG. 10 is a schematic perspective view showing a modified example of the bag filter according to the present invention.

FIG. 11 is an explanatory view schematically showing a flow of a gas flow in the bag filter.

FIG. 12 is an explanatory view showing an example of an expanded shape of a conventional inflatable seat belt device having an expanded body having a knitted fabric structure.

FIG. 13 is a schematic temperature distribution diagram showing a gas temperature distribution in an expansion structure of the inflatable seat belt device shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Inflatable seat belt device 2 Shoulder belt 3 Tongue 4 Buckle device 5 Slip guide 6, 9 Retractor (ELR) 7 Wrap belt 10 Webbing 20 Cover 21 Inner belt 22 Tube 23 Knitted fabric 25 Inflatable structure 26 Bag filter 27 Skirt 31 End Metal fitting 32 Caulking metal fitting 33 Tongue pipe 41 Housing 43 Gas generator 44 Buckle body 50 Press button

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60R 21/18 B60R 22/14

Claims (4)

(57) [Claims] 1. A bag which is kept in a band shape when normally mounted, and into which gas generated by gas generating means which operates in response to an operation signal from a collision detection unit is introduced, and is inflated and deployed in a substantially spindle shape. An inflatable structure having a convex portion, a webbing provided over at least a range in which the inflatable structure abuts an occupant, and a gas introduction passage from the gas generating means fixed to an end of the inflatable structure. In an inflatable seat belt device including a tongue and a buckle device to which the tongue is detachably fitted and locked, the inflatable structure has an elastic inflatable body inserted into the bag-shaped portion, and the elastic inflatable body includes It was ejected from the gas generating means
An inflatable seat belt device , wherein gas is introduced through a filter extending into the elastic inflatable body and is inflated and deployed. 2. The inflatable seat belt device according to claim 1, wherein said filter is a cylindrical bag filter inserted into said elastic inflatable body. 3. The inflatable seat belt device according to claim 2, wherein the bag filter is a woven fabric of heat-resistant fiber. 4. The inflatable seat belt device according to claim 1, wherein said elastic inflatable body is a silicone rubber tube.