JP2002053008A - Seat belt device having retractor for seat belt with energy absorbing mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat belt device having a retractor for a seat belt with an energy absorbing mechanism capable of improving the energy absorbing performance without impairing the miniaturization of the retractor, miniaturizing the seat belt device, and improving the safety of an occupant. SOLUTION: This seat belt device has an energy absorbing member 200 located between a locking base 5 and a bobbin 3, and comprising a base engagement part engaged with the locking base 5 and a bobbin engagement part engaged with the bobbin 3, and the energy absorbing member 200 permits the relative rotation of the locking base 5 and the bobbin 3 by the plastic deformation of at least one of the base engagement part and the bobbin engagement part when the load in the webbing drawing-out direction acting on the bobbin 3 in the operation of an emergency locking means, becomes more than a predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat belt device for restraining an occupant or the like of a vehicle to a seat, and more particularly to a seat belt device provided with a seat belt retractor having an energy absorbing mechanism.

[0002]

2. Description of the Related Art Conventionally, in a seatbelt device for holding a vehicle occupant or the like safely in a seat, generally, a retractor for a seatbelt which winds a webbing so as to be able to be pulled out is used for sudden acceleration, collision or deceleration. An emergency locking retractor is used which has an emergency locking mechanism that physically locks the webbing drawer by responsive inertial sensing means to effectively and safely restrain the occupant.

[0003] Such an emergency lock type retractor is provided at one end of a winding shaft on which webbing is wound, such as a seat belt retractor disclosed in Japanese Patent Publication No. 59-21624. In some cases, the engaging member is provided with a lock means capable of engaging the engaged portion of the retractor base in a vehicle emergency to prevent the winding shaft from rotating in the webbing withdrawing direction.

[0004] In the locking means, a locking mesh portion formed in a winding shaft through-hole of the retractor base through which the winding shaft passes, or an internal gear plate provided in parallel with the winding shaft through-hole. The formed ratchet teeth are used as engaged portions. A lock plate or a locking claw that rotates together with the winding shaft is used as an engagement member. In the event of a vehicle emergency, the engaging member and the engaged portion are engaged to prevent rotation of the winding shaft in the webbing pull-out direction.

[0005] However, when the impact force due to the collision is large, the webbing tension increases with the passage of time after the collision, so that the occupant's body suddenly decelerates and the load applied to the occupant from the webbing increases. . Therefore, when the load acting on the webbing is equal to or greater than a predetermined value set in advance, the webbing is extended by a predetermined amount to provide an energy absorbing mechanism that absorbs an impact generated on the occupant's body, thereby more reliably securing the occupant's body. Various seat belt retractors designed to protect the seat belt have been proposed. A seat belt retractor having such a configuration is described in JP-A-46-7710.
"Especially energy absorbing devices for safety belts" are known.

The energy absorbing mechanism has a substantially cylindrical bobbin around which a webbing is wound, and is inserted through the center of the bobbin and one end is integrally connected to the bobbin, and is rotatably supported by a retractor base. A winding shaft, a locking base integrally connected to the other end of the winding shaft, and a locking base that is engaged with a retractor base in a vehicle emergency to rotate the bobbin in a webbing pull-out direction. Emergency locking means for blocking.
When the load in the webbing pull-out direction acting on the bobbin at the time of the operation of the emergency locking means is equal to or more than a predetermined value, the winding shaft undergoes a torsional deformation, thereby allowing the bobbin to rotate in the webbing pull-out direction and allowing the impact energy to be reduced. Perform absorption. That is, the winding shaft that passes through the center of the bobbin is a so-called torsion bar (torsion bar), and when the load acting on the bobbin in the webbing pull-out direction is equal to or greater than a predetermined value, the torsion bar itself is twisted around the axis. This twisting allows the webbing to be pulled out by an amount corresponding to the rotation of the bobbin in the webbing pulling-out direction, relaxes the occupant restraining force by the webbing, and reduces the impact acting on the occupant from the webbing.

[0007]

However, the impact at the time of a collision differs depending on the vehicle structure. Therefore, in order to sufficiently protect the occupant's body, for example, a set load at which the energy absorbing mechanism starts operating (a so-called energy absorbing load, which is actually a webbing tension at which energy absorption starts), It is required that the amount of deformation (actually, the amount of extension of the webbing) at the time of shock absorption be changed in design in accordance with the vehicle structure and the like.

When the webbing is pulled out by the energy absorbing mechanism, the occupant moves in the collision direction accordingly. At that time, in order to prevent the occupant's body from colliding with the vehicle interior wall, etc., in recent vehicles, by bulging between the occupant and the vehicle interior wall, etc. in a vehicle emergency, the occupant's body is received. Equipped with an SRS airbag system that protects the occupant's body, measures are taken to improve the occupant's safety in cooperation with the seat belt device. When such an SRS airbag system is provided, the SRS
In order to maximize the effect of the airbag system safely and maximally, it is required to change the characteristics of the energy absorbing mechanism. For example, in the early stage of a collision before the occupant comes into contact with the inflated airbag, a large energy absorption load is secured to minimize the movement of the occupant, and during the late collision when the airbag begins to restrain the occupant, the energy absorption load is increased. Lowering the airbag system and entrusting occupant protection to the airbag system.

From the viewpoint of optimizing the energy absorption load according to the difference in the vehicle structure and sharing the role with the SRS airbag system, the energy absorption mechanism has a change in characteristics such as the energy absorption load. It has been required to be flexible and capable of designing.

[0010] Therefore, an object of the present invention is to solve the above-mentioned problems, and an energy absorbing mechanism of a seat belt retractor can have an energy absorbing characteristic in which an energy absorbing load changes during operation. It is possible to easily set the energy absorption load higher without sacrificing the compactness of the retractor, to reduce the size of the seatbelt device and improve occupant safety by improving the energy absorption characteristics. An object of the present invention is to provide a seatbelt device provided with a retractable seatbelt retractor having an energy absorbing mechanism.

[0011]

SUMMARY OF THE INVENTION The object of the present invention is to provide a bobbin around which a webbing is wound, and a bobbin inserted through the center of the bobbin and having one end integrally connected to the bobbin to be rotatable on a retractor base. And a locking base integrally connected to the other end of the winding shaft, and in a vehicle emergency, engaging the locking base with the retractor base to pull out the webbing of the bobbin. Emergency lock means for preventing rotation to
When the load in the webbing pull-out direction acting on the bobbin at the time of activation of the emergency locking means is equal to or more than a predetermined value, the winding shaft undergoes torsional deformation, thereby allowing the bobbin to rotate in the webbing pull-out direction and absorbing impact energy. A seat belt retractor provided with an energy absorbing mechanism-equipped seat belt retractor functioning as an energy absorbing mechanism that performs energy rotation between the locking base and the bobbin when the locking base and the bobbin rotate relative to each other. The present invention is achieved by a seatbelt device including a seatbelt retractor with an energy absorbing mechanism, which is provided with an energy absorbing means for absorbing air.

According to the above configuration, when the load applied to the bobbin in the webbing withdrawal direction becomes greater than or equal to a predetermined value when the emergency locking means is activated, both the winding shaft and the energy absorbing means function as energy absorbing mechanisms. Operates to absorb the impact energy of a vehicle emergency. Therefore, the energy absorbing load of the entire retractor is the sum of the energy absorbing load when the winding shaft undergoes torsional deformation and the energy absorbing load by the energy absorbing means. As compared with the conventional energy absorbing device that absorbs energy at the time, the energy absorbing load can be increased by the amount absorbed by the energy absorbing means, and it becomes easy to secure a high energy absorbing load.

In addition, the energy absorbing region by the energy absorbing means can be set independently of the energy absorbing region due to the torsional deformation of the winding shaft. For example, by setting the energy absorption area by the energy absorbing means to overlap a part of the energy absorption area due to the torsional deformation of the winding shaft, in a part of the energy absorption area due to the torsional deformation of the winding shaft, While ensuring a high energy absorption load by the sum of both energy absorption loads, in the range where both energy absorption regions do not overlap, set a low energy absorption load only by the energy absorption effect due to the torsional deformation of the winding shaft. Can be. In this way, the energy absorbing mechanism of the seat belt retractor can have an energy absorbing characteristic in which the energy absorbing load changes during operation.

Further, the adjustment of the energy absorbing load of the entire retractor can be performed not only by changing the shaft diameter and the material of the winding shaft, but also by changing the size, shape, and material of the portion of the energy absorbing means that absorbs the energy. Are related, and various elements are related. For example, a desired energy absorption load can be realized by changing the design of the remaining elements without relying on an increase in the shaft diameter of the winding shaft, a change in material, and the like. That is, it is possible to easily set the energy absorbing load without sacrificing the compactness of the retractor by reducing the diameter of the winding shaft or the bobbin of the retractor. If the dimensions and materials of both the take-up shaft and the energy absorbing means can be changed, adjust the energy absorbing load and the energy absorbing area on both sides so that the specific structure can be adjusted according to differences in vehicle structure. It can easily respond to demands for various energy characteristics and can flexibly respond to various needs.

Accordingly, the energy absorbing performance can be improved without sacrificing the compactness of the retractor by reducing the diameters of the winding shaft and the bobbin of the retractor, and the seat belt device can be downsized. Thus, the safety of the occupant can be improved by improving the energy absorption characteristics. Preferably, a plastically deformable energy absorbing member interposed between the locking base and the bobbin can be used as the energy absorbing means. In this case, energy is absorbed by plastic deformation.

Preferably, in the seat belt device provided with the above-mentioned seat belt retractor having an energy absorbing mechanism, the energy absorbing means is interposed between the locking base and the bobbin, and is connected to the locking base. An energy absorbing member having a base engaging portion engaged with the bobbin and a bobbin engaging portion engaging with the bobbin, the energy absorbing member acting on the bobbin when the emergency locking means is actuated; When is larger than a predetermined value, at least one of the base engaging portion and the bobbin engaging portion undergoes plastic deformation to allow relative rotation between the locking base and the bobbin. In this case, the energy absorbing member is an independent component interposed between the locking base and the bobbin. For example, even if the outer diameter of the bobbin and the take-up shaft is not changed, the energy absorbing member can be a part of the energy absorbing member that is plastically deformed. The energy absorption characteristics of the entire retractor can be adjusted only by changing the dimensions and the material. Further, if each of the base engaging portion and the bobbin engaging portion of the energy absorbing member is configured to be plastically deformed when a load in the webbing pull-out direction acting on the bobbin at the time of operating the emergency locking means becomes a predetermined value or more, It is also possible to easily adjust the increase or decrease of the absorption region, and to form more various energy absorption characteristics.

Preferably, in the seat belt device provided with the above-mentioned seat belt retractor having an energy absorbing mechanism, the energy absorbing means is a locking base integrally formed on an end face of the bobbin opposed to the locking base. An engaging portion is engaged with a locking portion provided on the locking base, and when a load acting on the bobbin in the webbing pull-out direction becomes greater than a predetermined value when the emergency locking means is operated, the locking portion of the locking base is locked. It is preferable that at least one of the locking base engaging portion of the bobbin and the locking base is plastically deformed to allow relative rotation between the locking base and the bobbin. In this way, by combining two different energy absorbing mechanisms, it is possible to secure a high energy absorbing load or to secure a high-performance energy absorbing performance in which the energy absorbing load changes during operation. Since it is integrated with the bobbin, increase in the number of components of the retractor can be suppressed, and reduction in cost can be promoted.

Preferably, in the seat belt device provided with the above-mentioned seat belt retractor having an energy absorbing mechanism, the energy absorbing means has a flat energy absorbing shape which engages with both the locking base and the bobbin. The energy absorbing member is disposed in parallel with the end face of the bobbin, and when the load in the webbing pull-out direction acting on the bobbin at the time of activation of the emergency locking means becomes a predetermined value or more, the energy absorbing member is plastically deformed. , The relative rotation between the locking base and the bobbin may be allowed. The thickness of the flat energy absorbing member is, for example, 0.5 mm to 1.5 mm.
mm. By doing so, it is possible to suppress the dimensional expansion of the retractor in the bobbin axis direction due to the provision of the energy absorbing member. Therefore,
Energy absorption performance can be improved without sacrificing compactness of the retractor. Further, the energy absorption characteristics of the entire retractor can be easily adjusted only by changing the hardness, thickness, material, shape of the engaging portion, and the like of the energy absorbing member.

Preferably, in the seat belt device provided with the seat belt retractor having the energy absorbing mechanism, the energy absorbing means is interposed between the locking base and the bobbin, and the locking base and the bobbin. When the load in the webbing pull-out direction acting on the bobbin when the emergency locking means is actuated becomes greater than or equal to a predetermined value, at least one of the locking base and the bobbin is plastically deformed by the engaging member. By deforming, it is preferable that the relative rotation between the locking base and the bobbin is allowed. The engaging member has a size and a shape enough to be completely received by at least one of the locking base and the bobbin, and the arrangement of the engaging member causes an increase in dimension of the retractor in the axial direction of the bobbin. It is preferable to use the one without the particle, for example, a small spherical one can be used. In this way, the energy absorption performance can be improved without sacrificing the compactness of the retractor.

Further, the object of the present invention is to provide a substantially cylindrical bobbin around which a webbing is wound, a center of the bobbin being inserted, and one end being integrally connected to the bobbin to be rotatable on a retractor base. And a locking base integrally connected to the other end of the winding shaft. In the event of a vehicle emergency, the locking base is engaged with a retractor base to pull out the bobbin in the webbing pull-out direction. Emergency lock means for preventing the rotation of the bobbin. When the load in the webbing pull-out direction acting on the bobbin when the emergency lock means is actuated becomes greater than a predetermined value, the webbing withdrawal of the bobbin is caused by torsional deformation of the winding shaft. A seat belt with an energy absorbing mechanism that functions as an energy absorbing mechanism that absorbs impact energy by allowing rotation in the direction. A seat belt apparatus provided with a tractor, as an energy absorbing means for absorbing energy during relative rotation between the locking base and the bobbin, the portion facing the said locking base and the bobbin,
A surface contact portion that comes into surface contact with each other and generates sliding resistance when the locking base and the bobbin are rotated relative to each other is provided, and absorption of impact energy in a vehicle emergency is reduced by the sliding resistance of the surface contact portion between the locking base and the bobbin. And a torsional deformation of the take-up shaft. This is achieved by a seat belt device provided with a seat belt retractor with an energy absorbing mechanism.

According to the above configuration, both the surface contact portion and the winding shaft provided at the opposing portion between the locking base and the bobbin as energy absorbing means operate as energy absorbing mechanisms. By combining two different energy absorbing mechanisms, it is possible to secure a high energy absorbing load and to secure a high-performance energy absorbing performance in which the energy absorbing load changes during operation. Since the contact portion is formed integrally with a part of the locking base and the bobbin, an increase in the number of components of the retractor can be suppressed, and a reduction in cost can be promoted. Further, the surface contact portion between the locking base and the bobbin that generates sliding resistance may be a cylindrical surface or a circumferential surface on which the locking base and the bobbin are fitted so as to be relatively rotatable. In this way, the sliding resistance that exhibits the effect of absorbing collision energy is limited to a relative rotation range effective for energy absorption within one rotation as in the case of realizing energy absorption by plastic deformation or the like of the engaging portion. Even when the relative rotation between the locking base and the bobbin exceeds one rotation, stable energy absorption performance can be secured throughout the relative rotation range, and a large increase in the amount of energy absorption can be realized. it can.

The above-described adjustment of the sliding resistance at the surface contact portions includes selection of rough surface processing of the sliding surface of each surface contact portion, setting of increase / decrease of the contact area, selection of a combination of materials of the sliding surfaces, and the like. It is good to set it from various kinds of elements. If the configuration is such that the sliding resistance is set from various types of elements, for example, even if it is difficult to change some elements due to limitations on dimensions, etc., the sliding resistance to be secured by changing other elements can be increased. It can be adjusted relatively easily to any required value. Here, as a material having a large sliding resistance in the surface contact portion, for example, there is a combination of aluminum and the like, but other materials may be used as long as a sliding resistance of a predetermined level or more can be secured.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a seatbelt device having a seatbelt retractor with an energy absorbing mechanism according to the present invention will be described below in detail with reference to the drawings. FIGS. 1 to 6 show a first embodiment of a seat belt device provided with a seat belt retractor with an energy absorbing mechanism according to the present invention, and FIG. 1 is used in the seat belt device according to the present invention. Front longitudinal sectional view of a first embodiment of a seat belt retractor with an energy absorbing mechanism, FIG. 2 is an exploded perspective view of a main part of the seat belt retractor shown in FIG. 1, and FIG. FIG. 4 is a perspective view of the shaft, the locking base, the energy absorbing means, and the bobbin. FIG. 4 is a longitudinal sectional view of an assembled state of the winding shaft, the locking base, the energy absorbing means, and the bobbin shown in FIG. 3, and FIG.
6A is a longitudinal sectional view showing a state in which the energy absorbing means is plastically deformed in the assembled state shown in FIG. 6, FIG. 6A is an energy absorption characteristic diagram of the seat belt retractor shown in FIG.
(B) is an energy absorption characteristic diagram in a case where only a winding shaft is provided as an energy absorption mechanism.

The retractor 100 for a seat belt with an energy absorbing mechanism shown in FIG. 1 has a substantially cylindrical bobbin 3 on which webbing is wound, a center of the bobbin 3 being inserted, and one end side (in FIG. 1, A winding shaft 2 integrally joined to the bobbin 3 and rotatably supported by the retractor base 1; and a substantially disc-shaped integrally joined to the other end of the winding shaft 2. Locking base 5, emergency locking means 300 for engaging the locking base 5 with the retractor base 1 in the event of a vehicle emergency to prevent the bobbin 3 from rotating in the webbing pull-out direction, and the locking base 5 and the bobbin 3. And an energy absorbing member 200 functioning as an energy absorbing means when the locking base 5 and the bobbin 3 are rotated relative to each other.

The retractor base 1 is formed by press-forming a metal plate so that left and right side plates 1a and 1b rise from both sides of a back plate 1c fixed to a vehicle body and have a substantially U-shaped cross section. A winding shaft 2 combined with the bobbin 3 is rotatably bridged at a position facing the left and right side plates 1a and 1b. Side plate 1 of the retractor base 1
A known take-up spring device (not shown) that constantly urges the bobbin 3 in the webbing take-up direction is provided at one end of the take-up shaft 2 through which the b is inserted.

A bobbin connecting portion 2a is formed at one end of the winding shaft 2 so as to be rotatable integrally with the bobbin 3. On the other end, a bobbin connecting portion rotatable with the locking base 5 is formed. A fulfilling locking base coupling part 2b is formed. The bobbin coupling portion 2a has a hexagonal cross section, and is inserted into a hexagonal cross-section insertion hole 40a of the sleeve 40 fitted in a fitting recess 3a having a triangular cross section formed at one end of the bobbin 3. As a result, the bobbin 3 is integrally rotatably coupled thereto.

The locking base coupling portion 2b has a hexagonal cross section, and is inserted into a hexagonal cross section insertion hole 8a of a cylindrical boss 8 protruding from the bobbin-side end surface of the locking base 5. Thus, it is integrally rotatably coupled to the locking base 5 (see FIG. 3). The locking base 5 is provided at the locking base side end of the bobbin 3.
A fitting recess 9 for receiving the boss portion 8 is formed in a concave shape, and the bobbin 3 is rotatably supported on the winding shaft 2 via the fitting recess 9.

The winding shaft 2 is provided with the emergency locking means 30.
When the load in the webbing pull-out direction acting on the bobbin 3 at the time of the operation of 0 becomes equal to or greater than a predetermined value, and accordingly, a rotational torque equal to or more than a predetermined value acts between the coupling portions 2a and 2b,
A torsional deformation occurs between these coupling portions 2a and 2b. Thus, the winding shaft 2 functions as an energy absorbing mechanism for absorbing the impact energy acting on the occupant while allowing the bobbin 3 to rotate in the webbing withdrawing direction.

As the specific structure of the emergency lock means 300, various known structures can be adopted. For example,
In the case of the first embodiment, a pole 16 having a locking tooth 16a at its tip is rotatably supported on a support shaft 7 erected on the outer surface of the locking base 5. Also, the side plate 1
a outside of the through hole 20 opened in the
Toothed ratchet 2 provided on its inner periphery with engaging internal teeth that can engage
1 is attached. The emergency locking means 300 disposed in the center cover 35 engages the locking teeth 16a of the pawl 16 with the engaging internal teeth 25 of the internal tooth ratchet 21 in the event of a vehicle emergency, so that the locking base 5
Is prevented from rotating in the webbing pull-out direction.

As shown in FIG. 3, the energy absorbing member 200 includes a base engaging portion 201 for engaging with the locking base 5 and a bobbin engaging portion 202 for engaging with the bobbin 3. Independent parts. In the case of the present embodiment, the base engaging portion 201 has a configuration in which a separating portion 201b is provided on a part of a cylindrical peripheral wall 201a extending in the central axis direction. The relative rotation of the locking base 5 with respect to the bobbin 3 is restricted by engaging the locking portion 204 protruding from the opposing portion of the locking base 5 with the separation portion 201b. The bobbin engaging portion 202 is a locking piece that protrudes radially outward from the outer periphery of a flange portion 205 connected to one end of the cylindrical base engaging portion 201. The relative rotation of the bobbin 3 with respect to the locking base 5 is regulated by the engagement of the bobbin engaging portion 202 with a locking portion 206 which is provided on the end surface of the bobbin 3 on the locking base side.

The above energy absorbing member 200 is shown in FIG.
As shown in the figure, it is assembled between the locking base 5 and the bobbin 3. Then, the emergency locking means 300
When the load in the webbing pull-out direction acting on the bobbin 3 at the time of the operation becomes a predetermined value or more and the locking base 5 and the bobbin 3 start relative rotation by the start of the torsional deformation of the winding shaft 2 described later, as shown in FIG. The locking portion 2
A radially inward load F acts on the edge of the cut-off portion 201b from the tapered surface 204a of the substrate 04. This load F
Accordingly, the base engaging portion 201 undergoes plastic deformation, whereby relative rotation between the locking base 5 and the bobbin 3 is allowed.

Next, the operation of the seat belt retractor 100 of the first embodiment will be described. When the emergency locking means 300 operates in the event of a vehicle emergency such as a collision, first,
The rotation of the locking base 5 connected to the other end of the winding shaft 2 in the webbing pull-out direction is prevented. When a rotation torque of a predetermined value or more acts on one end of the winding shaft 2 via the bobbin 3 due to the load acting on the webbing, torsional deformation of the winding shaft 2 starts, and the amount of torsional deformation of the winding shaft 2 is calculated. Only when the bobbin 3 rotates in the webbing pull-out direction, the impact energy is absorbed. Also, when relative rotation occurs between the bobbin 3 and the locking base 5 due to the start of the torsional deformation of the winding shaft 2, as described above, the energy absorbing member 200 is moved from the locking portion 204 of the locking base 5. Due to the load acting on the base engaging portion 201, plastic deformation of the base engaging portion 201 also starts. The plastic deformation of the base engaging portion 201 also absorbs impact energy.

That is, in the event of a vehicle emergency, the emergency locking means 3
When the load 00 in the webbing pull-out direction acting on the bobbin 3 becomes greater than or equal to a predetermined value, both the energy absorbing member 200 as energy absorbing means and the winding shaft 2 operate as energy absorbing mechanisms, respectively. Absorbs impact energy in vehicle emergencies. Therefore, as shown in FIG. 6A, the energy absorbing load of the entire retractor is the energy absorbing load f1 when the winding shaft 2 undergoes torsional deformation and the energy absorbing load f1 when the energy absorbing member 200 undergoes plastic deformation. This is the total sum f3 of the energy absorption loads f2. For example, as shown in FIG. 6B, when compared with a conventional structure in which the winding shaft 2 absorbs energy in the event of a vehicle emergency only by torsional deformation, the energy absorbing load is equal to the absorbed amount of the energy absorbing member 200. And it is easy to secure a high energy absorption load.

Further, as shown in FIG.
The energy absorption region A1 due to the plastic deformation of the energy absorbing member 200 can be set independently of the energy absorption region A1 due to the torsional deformation. For example, by setting the energy absorption region A2 due to the plastic deformation of the energy absorbing member 200 to partially overlap the energy absorption region A1 due to the torsional deformation of the winding shaft 2, the energy absorption region A2 due to the torsional deformation of the winding shaft 2 is set. In part of the energy absorption area,
A high energy absorption load is secured by the sum of both energy absorption loads. In addition, as long as the two energy absorption regions do not overlap, a low energy absorption load can be set only by the energy absorption effect due to the torsional deformation of the winding shaft 2. In this way, the energy absorbing mechanism of the seat belt retractor can have an energy absorbing characteristic in which the energy absorbing load changes during operation.

Further, the adjustment of the energy absorbing load of the entire retractor involves not only the change of the shaft diameter and the material of the winding shaft 2 but also the adjustment of the portion (the base engaging portion 201) where the energy absorbing member 200 undergoes plastic deformation. Changes in dimensions, shapes, and materials are involved, and various elements are involved. For example, winding shaft 2
It is also possible to realize a desired energy absorption load by changing the design of the remaining elements without relying on an increase in the shaft diameter or a change in material. That is, the energy absorption load can be easily set higher without sacrificing the compactness of the retractor by reducing the diameters of the winding shaft 2 and the bobbin 3 of the retractor. If the dimensions and materials of both the winding shaft 2 and the energy absorbing member 200 can be changed, the energy absorbing load and the energy absorbing region are adjusted on both sides to adjust for the difference in vehicle structure and the like. It can easily respond to demands for unique energy characteristics and can flexibly respond to various needs.

Therefore, the energy absorption performance can be improved without sacrificing the compactness of the retractor by reducing the diameter of the winding shaft 2 and the bobbin 3 of the retractor.
The size of the seat belt device can be reduced, and the safety of the occupant can be improved by improving the energy absorption characteristics.

In the first embodiment, when the load in the webbing pull-out direction acting on the bobbin 3 when the emergency locking means 300 is actuated becomes greater than a predetermined value, only the base engaging portion 201 becomes plastic. Although the configuration is such that the bobbin engaging portion 202 is plastically deformed, the configuration may be modified instead. Further, if each of the base engaging portion 201 and the bobbin engaging portion 202 is configured to be plastically deformed, the increase and decrease of the energy absorption region can be easily adjusted, and more various energy absorption characteristics can be formed. .

Further, in the above-described first embodiment, the energy absorbing means uses the energy absorbing member 200 which is an independent component. However, the energy absorbing means may be provided integrally with a bobbin or a locking base. FIG. 7 is an exploded perspective view of a main part of a second embodiment of the seat belt retractor according to the present invention. In the second embodiment, the energy absorbing means is integrally formed. That is, the energy absorbing means of the present embodiment is
As shown in FIG. 8, a base engaging portion 211 integrally formed on the end surface of the bobbin 31 facing the engaging portion is engaged with a locking portion 214 provided on the locking base 51. Thus, the locking base 51 and the bobbin 31
And the emergency lock means 3
When the load acting on the bobbin 31 in the webbing withdrawal direction at the time of the operation of 00 becomes a predetermined value or more, as shown in FIG. 9, the base engaging portion 211 undergoes plastic deformation, thereby causing the locking base 51 and the bobbin 31 to move. Allows relative rotation between them to absorb impact energy.

In this embodiment, the base engaging portion 211
Has the same structure as the base engaging portion 201 of the energy absorbing member 200 shown in the first embodiment. In other words, the base engaging portion 211 has a configuration in which a separating portion 211b is provided on a part of a cylindrical peripheral wall 211a extending in the center axis direction, and the base engaging portion 211 is protruded from the facing portion of the locking base 51 at the separating portion 211b. The engagement of the locking portion 214 regulates relative rotation between the locking base 51 and the locking base 51. In addition,
The coupling structure of the bobbin 31 with the winding shaft 2 and the coupling structure of the locking base 51 with the winding shaft 2 are the same as those of the bobbin 3 and the locking base 5 shown in the first embodiment. Omitted.

In this manner, as in the case of the first embodiment, a combination of two different energy absorbing mechanisms can be used.
As shown in FIG. 10, it is possible to secure a high energy absorption load f4 and to secure energy absorption performance in which the energy absorption load changes during operation. Further, since the energy absorbing means is integrated with the bobbin 31, an increase in the number of components of the retractor can be suppressed, and a reduction in cost can be promoted.

The energy absorbing structure of the energy absorbing means according to the present invention is not limited to plastic deformation of parts. For example, when the bobbin and the locking base are rotated relative to each other, a large sliding resistance may be generated between the bobbin and the locking base, and the shock resistance may be absorbed by the sliding resistance. FIG. 11 is an exploded perspective view of a main part of a third embodiment of the seat belt retractor according to the present invention. FIG. 12 is a sectional view when the components shown in FIG. 11 are assembled. In the third embodiment, a sliding resistance between a bobbin and a locking base is used for absorbing impact energy in a vehicle emergency.

The seat belt retractor according to the third embodiment has a substantially cylindrical bobbin 32 around which webbing is wound.
A winding shaft 2 which is inserted through the center of the bobbin 32 and one end of which is integrally connected to the bobbin 32 and which is rotatably supported by a retractor base; Locking base 52, which is coupled to the base, and emergency locking means (not shown) for engaging the locking base 52 with a retractor base to prevent the bobbin 32 from rotating in the webbing pull-out direction in a vehicle emergency. ing.

The structure for connecting the bobbin 32 to the winding shaft 2 and the structure for connecting the locking base 52 to the winding shaft 2 are as follows.
Since the configuration is the same as that of the bobbin 3 and the locking base 5 shown in the first embodiment, the description is omitted.

Further, in the seat belt retractor of the third embodiment, when the load applied to the bobbin 32 in the webbing pull-out direction exceeds a predetermined value when the emergency locking means is actuated, the bobbin 32 in the webbing pull-out direction can be moved. As the energy absorbing mechanism for absorbing impact energy by allowing rotation, the winding shaft 2 for absorbing impact energy by torsional deformation, and energy absorbing means 220 for absorbing impact energy separately from the winding shaft. It has. Absorption of impact energy during vehicle emergency
The energy is absorbed by the energy absorbing means 220 and the winding shaft 2.

However, the energy absorbing means 220 in the third embodiment is in contact with the opposing portions of the locking base 52 and the bobbin 32 in surface contact with each other, and the sliding resistance is exerted when the locking base 52 and the bobbin 32 rotate relative to each other. Are provided, and relative rotation between the locking base 52 and the bobbin 32 is regulated by sliding resistance between the surface contact portions 221 and 222. Here, in order to increase the sliding resistance in the surface contact portions 221 and 222, the bobbin 32 and the locking base 52 are preferably made of aluminum having a large friction coefficient. ,
Other materials may be used.

According to the above configuration, the locking base 52 as the energy absorbing means 220 and the bobbin 3
2, the surface contact portions 221 and 222 provided on the facing portion and the winding shaft 2 each operate as an energy absorbing mechanism, and in combination of two different energy absorbing mechanisms,
As shown in FIG. 13, a high energy absorption load f4 is ensured. The surface contact portions 221 and 222 constituting the energy absorbing means 220 are
In addition, since it is formed integrally with a part of the bobbin 32, the increase in the number of components of the retractor can be suppressed, and the cost can be reduced.

In the present embodiment, the surface contact portion 2 of the locking base 52 and the bobbin 32 that generates sliding resistance.
21 and 222 are cylindrical surfaces or circumferential surfaces on which the locking base 52 and the bobbin 32 are fitted so as to be relatively rotatable. As a result, the sliding resistance exerting the absorbing effect of the collision energy is reduced by the relative rotation effective for energy absorption as in the first and second embodiments in which the energy absorption is realized by plastic deformation of the engaging portion. The area is not limited to one rotation. As shown in FIG. 13, even when the relative rotation between the locking base 52 and the bobbin 32 exceeds one rotation, stable energy absorption performance can be ensured over the entire relative rotation range, and the energy absorption amount is significantly increased. Can be realized.

The adjustment of the sliding resistance in the surface contact portions 221 and 222 is performed by adjusting the respective surface contact portions 221 and 222.
Selection of rough surface processing of the sliding surface of No. 22, setting of increase / decrease of contact area,
The configuration may be set from various elements such as selection of a combination of materials for the sliding surfaces. If the configuration is such that the sliding resistance is set from various types of elements, for example, even if it is difficult to change some elements due to limitations on dimensions, etc., the sliding resistance to be secured by changing other elements can be increased. It can be adjusted relatively easily to any required value.

FIG. 14A is an exploded perspective view of a main part of a fourth embodiment of the seat belt retractor according to the present invention. In the fourth embodiment, a flat energy absorbing member 230 is used as energy absorbing means. The retractor for a seat belt according to the fourth embodiment includes a substantially cylindrical bobbin 33 around which webbing is wound,
A winding shaft 12 that is inserted through the center of the bobbin 33 and has one end (the left end in FIG. 14) integrally connected to the bobbin 33 and rotatably supported by the retractor base. A locking base 53 integrally connected to the other end of the bobbin, and emergency locking means for engaging the locking base 53 with the retractor base in a vehicle emergency to prevent the bobbin 33 from rotating in the webbing pull-out direction. I have. FIG. 14B is a perspective view of the locking base 53 viewed from the opposite side in the axial direction.

The structure for connecting the bobbin 33 to the winding shaft 12 and the structure for connecting the locking base 53 to the winding shaft 12 are the same as those of the bobbin 3 and the locking base 5 shown in the first embodiment. The description is omitted.

In the seat belt retractor of the fourth embodiment, as the energy absorbing mechanism, the take-up shaft 12 that absorbs impact energy by torsional deformation, and absorbs impact energy separately from the take-up shaft 12. And an energy absorbing member 230 for performing the operation. The impact energy in the event of a vehicle emergency is absorbed by the winding shaft 12 and the energy absorbing member 230. The energy absorbing member 230 is
It is arranged between the end face of the bobbin 33 and the locking base 53 in parallel with them.

The energy absorbing member 230 is composed of a disk-shaped member 230a. A circular through hole 231a is provided at the center of the disc-shaped member 230a. One locking recess 231b is provided at the opening edge of the through hole 231a. More specifically, the locking recess 231b is
It is provided on the peripheral surface that partitions 31a. Through hole 231
a and the engaging recess 231b constitute a base engaging portion 231. The cylindrical boss 58 of the locking base 53 shown in FIG. 14B is fitted into the through hole 231a. The locking projection 234 provided on the outer peripheral surface of the boss 58 is fitted into the locking recess 231b. Further, the tip of the boss 58 is connected to the energy absorbing member 23 of the bobbin 33.
It is received in the fitting recess 59 provided at the end on the 0 side. In the outer peripheral surface of the disk-shaped member 230a, locking recesses 23 as bobbin engaging portions are provided at a plurality of positions at equal intervals in the circumferential direction.
2 are provided.

Examples of the material of the energy absorbing member 230 include aluminum and mild steel. When the material is mild steel, for example, the plate thickness can be set to about 1.6 mm to 2.5 mm. Since the energy absorbing member 230 has a simple shape, it can be easily manufactured by press working or the like. In addition, because of the simple shape, the transportation of the energy absorbing member 230 and the storage and management of the energy absorbing member 230 in the retractor assembly process are easy.

As shown in FIG. 14B, a storage recess 53a for storing a part of the energy absorbing member 230 is provided on the end surface of the locking base 53 on the energy absorbing member 230 side. The storage recess 53 a is a ring-shaped groove provided on the outer periphery of the boss 58 and the locking projection 234. On the other hand, the energy absorbing member 230 of the bobbin 33
A substantially circular storage recess 33a for storing a part of the energy absorbing member 230 is also provided on the side end surface.
The energy absorbing member 230 is provided on the peripheral surface of the storage recess 33a.
The locking recess 2 of the disc-shaped member 230a is
A plurality of locking projections 236 that engage with the projections 32 are provided at equal intervals in the circumferential direction. That is, the outer shape of the storage recess 33a is substantially equal to the outer shape of the disk-shaped member 230a.

FIG. 15 is a front vertical sectional view of the seatbelt retractor 140 of the fourth embodiment. Winding shaft 1
The emergency locking means 310 is disposed outside the one side plate 11a of the retractor base 11 through which the end of the second locking base 53 is inserted. In the present embodiment, the other side plate 11b of the retractor base 11 is used.
The pretensioner 320 is disposed outside the box.
The pretensioner 320 rotates the winding shaft 12 and the bobbin 33 so as to remove the slack of the webbing that restrains the occupant in the event of a vehicle emergency, thereby tensioning the webbing. Further, a take-up spring device 330 that constantly urges the bobbin 33 in the webbing take-up direction is provided outside the pretensioner 320.

As shown in FIG. 15, a substantially disk-shaped energy absorbing member 230 is
And a storage space 233a defined by the storage recess 53a of the locking base 53. By providing the storage recesses 33a and 53a, the end of the bobbin 33 and the locking base 53 become slightly thinner. However, the energy absorbing member 230 is not provided with the storage recesses 33a, 53a.
, The predetermined strength of the bobbin 33 and the locking base 53 is ensured.

Next, the operation of the seat belt retractor 140 of the fourth embodiment will be described. When the emergency locking means 310 operates in the event of a vehicle emergency such as a collision, first,
The rotation of the locking base 53 connected to the other end of the winding shaft 12 in the webbing pull-out direction is prevented by the action of the pawl 16. Energy absorbing member 230 at this time
(A) is shown in FIG. Since the rotation of the locking base is prevented, the positions of the boss 58 and the locking projection 234 of the locking base are fixed.

Then, a rotating torque equal to or more than a predetermined value is generated via the bobbin 33 by the load acting on the webbing.
When acting on one end side of 2, the torsion deformation of the winding shaft 12 starts. The winding shaft 12 absorbs energy by its torsional deformation. The amount of torsion deformation of the winding shaft 12 is equivalent to the amount of bobbin 33
Is rotated in the webbing pull-out direction. At this time, the bobbin 33 rotates relative to the locking base 53.
At this time, as shown in FIG.
Is rotated together with the bobbin because the locking recess 232 provided on the outer peripheral surface thereof is engaged with the end surface of the bobbin.
However, the boss 58 of the locking base and the locking projection 2
34 does not rotate. Therefore, the inner peripheral surface of the disc-shaped member 230a is plastically deformed by the locking projection 234. Specifically, the locking recess 231b is expanded in the circumferential direction of the through hole 231a. By plastically deforming the disc-shaped member 230a by the locking projections 234 in this manner, energy absorption is performed separately from energy absorption due to torsional deformation of the winding shaft.

Then, as shown in FIG. 16 (c), when the disk-shaped member 230a makes one rotation and the inner peripheral surface of the disk-shaped member 230a is pierced by the locking projection 234, the energy is reduced. The energy absorption by the absorbing member 230 ends.

According to the present embodiment, since the energy absorbing member 230 is disk-shaped,
By disposing 30, the dimensional expansion of the retractor in the bobbin axis direction can be suppressed. Then, the energy absorption characteristics according to the first embodiment shown in FIG. 6 or the energy absorption characteristics similar to the energy absorption characteristics according to the second embodiment shown in FIG. 10 can be obtained. Therefore,
Energy absorption performance can be improved without sacrificing compactness. This embodiment is effective when using the pretensioner 320 which causes the dimension of the retractor to increase in the bobbin axis direction.

Since the energy absorbing member 230 has a simple shape, the manufacturing cost can be reduced. Further, the hardness, thickness, material,
The energy absorption characteristics can be easily adjusted by changing the shape of the engagement portion. For example, in the present embodiment, the inner peripheral surface of the disk-shaped member 230a is plastically deformed, but the outer peripheral surface of the disk-shaped member 230a may be plastically deformed.

FIG. 17A is an exploded perspective view of a main part of a fifth embodiment of the seat belt retractor according to the present invention. FIG. 17B is a perspective view of the locking base 54 viewed from the opposite side in the axial direction. The retractor for a seat belt according to the fifth embodiment has, as an energy absorbing mechanism, a winding shaft 12 that absorbs impact energy by torsional deformation, and energy absorbing means that absorbs impact energy separately from the winding shaft 12. And The energy absorbing means has a ring-shaped deformed portion 34 a provided on the end face of the bobbin 34 and a spherical engaging member 240. The impact energy in the event of a vehicle emergency is absorbed by the winding shaft 12 and the energy absorbing means. The configuration not shown is the same as that of the fourth embodiment shown in FIG.

One side of the ring-shaped deformed portion 34 a is embedded and fixed in the end face of the bobbin 34, and the other side protrudes from the end face of the bobbin 34. A first concave portion 246a for receiving the engaging member 240 and a second concave portion 246b are provided on the peripheral surface of the circular through hole at the center of the deformed portion 34a at predetermined intervals in the circumferential direction. The first recess 246a is smaller than the second recess 246b. The first concave portion 246a is the engagement member 2
It receives only a part of 40 and has a bottom surface (not shown) parallel to the end surface of bobbin 34. Second recess 24
Numeral 6b completely receives the entire engaging member 240, and here is formed in a groove shape extending along the axial direction of the through hole. Here, the center angle defined by the center of the through hole, the first concave portion 246a and the second concave portion 246b is 120.
Degree has been around. Examples of the material of the deformed portion 34a include aluminum and mild steel.

As shown in FIG. 17B, the end of the locking base 54 on the bobbin 34 side is provided with the deformed portion 34a.
A storage recess 53a is provided for storing a portion protruding from the end surface of the bobbin 34. The storage recess 53a
This is a ring-shaped groove provided on the outer periphery of the boss 58. The outer peripheral surface of the boss 58 is provided with a third concave portion 244 for receiving a part of the engaging member 240. Boss part 5
8 is received in the through hole of the deformed portion 34a. In the initial state of the seat belt retractor, the engagement member 240 is provided on the first bobbin 34 provided on the bobbin 34.
The third portion provided in the concave portion 246a and the locking base 54
It is completely received in the storage space defined by the recess 244. The engaging member 240 is smaller than the locking base 54 and the bobbin 34, and the provision of the engaging member 240 does not increase the axial dimension of the retractor.

Next, the operation of the seat belt retractor of the fifth embodiment will be described. When the emergency locking means 310 (see FIG. 15) operates in the event of a vehicle emergency such as a collision, first, the locking base 5 connected to the winding shaft 12
4 is prevented from rotating in the webbing pull-out direction by the action of the pole 16. FIG. 18A shows the state of the end surface of the bobbin 34 at this time. Since the rotation of the locking base is prevented, the position of the engagement member 240, a part of which is received by the locking base, is fixed. In the state shown in FIG. 18A, the upper part (substantially the upper half in the figure) of the engaging member 240 is received in the third concave portion of the locking base, and the lower part of the engaging member 240 in the figure (substantially the lower half in the figure) Part) is received in the first concave portion 246 a of the bobbin 34.

When the load acting on the webbing causes a rotation torque of a predetermined value or more to act on one end of the winding shaft via the bobbin 34 and torsional deformation of the winding shaft starts, the amount of torsional deformation of the winding shaft is increased. , The bobbin 34 is rotated in the webbing pull-out direction. At this time, the bobbin 34 rotates relative to the locking base 53. As shown in FIG. 18B, at this time, the deformed portion 34a is rotated together with the bobbin 34. However, since the engagement member 240 does not move, the edge of the through hole of the deformed portion 34a is plastically deformed by the engagement member 240. Specifically, the first recess 246a is expanded in the circumferential direction of the through hole. Thus, the engagement member 240
By plastically deforming the deformable portion 34a, energy absorption is performed separately from energy absorption due to torsional deformation of the winding shaft.

Then, as shown in FIG. 18 (c), when the engaging member 240 is received by the second concave portion 246b and is no longer engaged with the third concave portion 244 of the locking base, energy is absorbed by the energy absorbing means. Ends.

According to the present embodiment, since the engaging member 240 has a small spherical shape, the size of the retractor in the axial direction of the bobbin due to the provision of the engaging member 240 can be suppressed. Then, the energy absorption characteristics according to the first embodiment shown in FIG. 6 or the energy absorption characteristics similar to the energy absorption characteristics according to the second embodiment shown in FIG. 10 can be obtained. Therefore, the energy absorption performance can be improved without sacrificing compactness. Further, the present embodiment is directed to a pretensioner 32 which is a factor of increasing the dimension of the retractor in the bobbin axis direction.
This is effective when 0 (see FIG. 15) is used.

Further, since the engaging member 240 and the deformed portion 34a have simple shapes, the manufacturing cost can be reduced. Further, the energy absorption characteristics can be easily adjusted by changing the hardness and material of the deformed portion 34a, the shape of the first concave portion 246a in the initial state, and the like.

[0070]

According to the seatbelt device provided with the seatbelt retractor having the energy absorbing mechanism of the present invention, when the load applied to the bobbin in the webbing pull-out direction exceeds a predetermined value when the emergency locking means is operated, the winding is performed. Both the shaft and the energy absorbing means operate as energy absorbing mechanisms, respectively, to absorb impact energy in the event of a vehicle emergency. Therefore, the energy absorbing load of the entire retractor is the sum of the energy absorbing load when the winding shaft undergoes torsional deformation and the energy absorbing load by the energy absorbing means. As compared with the conventional energy absorbing device that absorbs energy at the time, the energy absorbing load can be increased by the amount absorbed by the energy absorbing means, and it becomes easy to secure a high energy absorbing load.

Further, the energy absorption area by the torsional deformation of the winding shaft and the energy absorption area by the energy absorbing means can be independently set. For example, the energy absorption area by the energy absorbing means is set to the energy absorption area of the winding shaft. By setting so as to overlap a part of the energy absorption region due to torsional deformation, in a part of the energy absorption region due to torsional deformation of the winding shaft, while securing a high energy absorption load due to the sum of both energy absorption loads. In a range where both energy absorption areas do not overlap, a low energy absorption load can be set only by the energy absorption effect due to the torsional deformation of the winding shaft, and the energy absorption mechanism of the seat belt retractor is in operation. Energy absorption characteristics in which the energy absorption load changes can be provided.

Further, the adjustment of the energy absorbing load of the entire retractor can be performed not only by changing the diameter and the material of the winding shaft, but also by changing the size, shape, and material of the portion of the energy absorbing means that absorbs the energy. However, because various types of elements are involved, it is possible to realize the desired energy absorption load by changing the design of the remaining elements without relying on, for example, expanding the shaft diameter of the winding shaft or changing the material. It is possible. That is, the energy absorption load can be easily set higher without sacrificing the compactness of the retractor by reducing the diameter of the winding shaft or the bobbin of the retractor. If the dimensions and materials of both the take-up shaft and the energy absorbing means can be changed, adjust the energy absorbing load and the energy absorbing area on both sides so that the specific structure can be adjusted according to differences in vehicle structure. It can easily respond to demands for various energy characteristics and can flexibly respond to various needs.

Accordingly, the energy absorption performance can be improved without sacrificing the compactness of the retractor by reducing the diameters of the winding shaft and the bobbin of the retractor, and the seat belt device can be downsized. Thus, the safety of the occupant can be improved by improving the energy absorption characteristics.

[Brief description of the drawings]

FIG. 1 is a first view of a seat belt retractor with an energy absorbing mechanism used in a seat belt device according to the present invention.
It is a front longitudinal section of an embodiment.

FIG. 2 is an exploded perspective view of a main part of the seat belt retractor shown in FIG.

FIG. 3 is a perspective view of a winding shaft, a locking base, an energy absorbing unit, and a bobbin shown in FIG. 2;

4 is a longitudinal sectional view of an assembled state of a winding shaft, a locking base, an energy absorbing unit, and a bobbin shown in FIG. 3;

FIG. 5 is a longitudinal sectional view showing a state in which the energy absorbing means undergoes plastic deformation in the assembled state shown in FIG. 4;

6A is an energy absorption characteristic diagram of the seat belt retractor shown in FIG. 1, and FIG. 6B is an energy absorption characteristic diagram in a case where only a winding shaft is provided as an energy absorption mechanism. .

FIG. 7 shows a second seatbelt retractor with an energy absorbing mechanism used in the seatbelt device according to the present invention.
It is an exploded perspective view of the important section of an embodiment.

8 is a cross-sectional view showing an engagement state between a locking portion of the locking base shown in FIG. 7 and a base engaging portion on a bobbin end surface.

FIG. 9 is a cross-sectional view showing a state in which the base engaging portion on the bobbin end face is plastically deformed by the locking portion of the locking base shown in FIG. 7;

10 is an energy absorption characteristic diagram of the seat belt retractor shown in FIG.

FIG. 11 is an exploded perspective view of a main part of a third embodiment of a seat belt retractor with an energy absorbing mechanism used in a seat belt device according to the present invention.

12 is a longitudinal sectional view of a main part of the energy absorption mechanism shown in FIG.

13 is an energy absorption characteristic diagram of the seat belt retractor shown in FIG.

FIG. 14 is an exploded perspective view of a main part of a fourth embodiment of a seat belt retractor with an energy absorbing mechanism used in a seat belt device according to the present invention.

FIG. 15 is a front vertical sectional view of the fourth embodiment.

FIG. 16 is a schematic diagram illustrating how the energy absorbing means of the fourth embodiment undergoes plastic deformation.

FIG. 17 is an exploded perspective view of a main part of a fifth embodiment of a seat belt retractor with an energy absorbing mechanism used in the seat belt device according to the present invention.

FIG. 18 is a schematic diagram illustrating a state in which a deformed portion of the fifth embodiment undergoes plastic deformation.

[Explanation of symbols]

1,11 retractor base 2,12 winding shaft (torsion bar) 3,31,32,33 bobbin 5,51,52 locking base 100,110 seat belt retractor with energy absorbing mechanism 200 energy absorbing member (energy absorbing member) Means) 201 Base engaging portion 202 Bobbin engaging portion 204 Locking portion 205 Flange portion 206 Locking portion 211 Base engaging portion 214 Locking portion 220 Energy absorbing means 221 and 222 Surface contacting part 230 Energy absorbing member (Energy absorbing means 240 engaging member (energy absorbing means) 300, 310 emergency locking means 320 pretensioner

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mitsuteru Owari 12, Kirihara-cho, Fujisawa-shi, Kanagawa Prefecture Nippon Seiko Co., Ltd. (72) Inventor Tomoji Igarashi 12, Kirihara-cho, Fujisawa-shi, Kanagawa Pref. 72) Inventor Takamitsu Kato 12 Kirihara-cho, Fujisawa-shi, Kanagawa F-term in NSK Ltd. (reference) 3D018 DA07 HA00 HB01 HC01 HC04 MA01

Claims (1)

[Claims] 1. A bobbin on which a webbing is wound, a winding shaft inserted through the center of the bobbin, one end of which is integrally connected to the bobbin and rotatably supported by a retractor base; A locking base integrally connected to the other end of the take-up shaft, and emergency locking means for engaging the locking base with the retractor base in a vehicle emergency to prevent the bobbin from rotating in the webbing pull-out direction. When the load in the webbing pull-out direction acting on the bobbin at the time of activation of the emergency locking means is equal to or more than a predetermined value, the winding shaft undergoes a torsional deformation, thereby allowing the bobbin to rotate in the webbing pull-out direction and providing impact energy. With a seat belt retractor with an energy absorbing mechanism that functions as an energy absorbing mechanism that absorbs air For a seat belt with an energy absorbing mechanism, characterized in that between the locking base and the bobbin, energy absorbing means for absorbing energy when the locking base and the bobbin are relatively rotated is provided. Seat belt device with retractor.