Retractor system for seat belt

Abstract

To provide a retractor system for seat belt that can correspond to restraint performance of various conditions depending on a crewman with a relatively simple configuration.SOLUTION: A retractor system for seat belt comprises a retractor having a first energy absorption mechanism that can deliver a webbing while absorbing energy when a load exceeding a specified value is added to the webbing, and comprises an additional energy absorption mechanism which can deliver a webbing onto a webbing crawl path extended from the retractor while absorbing energy when a load exceeding a second specified value different from the specified value is added to the webbing. The additional energy absorption mechanism is independent from the first energy absorption mechanism, and can be selectively operated.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a seat belt retractor system including a retractor having an energy absorption mechanism that enables the webbing to be unwound while absorbing energy when a load exceeding a predetermined value is applied to the webbing. [Background technology]

[0002] Conventionally, a retractor provided in a vehicle seat belt device winds and unwinds a webbing (seat belt) by rotating a spindle, and in the event of a vehicle collision, a locking mechanism locks the rotation of the spindle to prevent the webbing from being unwound. On the other hand, when the impact force of a collision is extremely large, the webbing tension increases with the passage of time after the collision, and the load applied to the occupant from the webbing increases. Therefore, the retractor is provided with an energy absorption mechanism that reduces the burden on the occupant's chest by unwinding a predetermined amount of the webbing while absorbing energy when the load acting on the webbing reaches or exceeds a preset value (see, for example, Patent Documents 1 and 2).

[0003] Various types of load limiters (force limiters) have been proposed as energy absorption mechanisms for retractors. For example, the simplest and most representative type (hereinafter, this may be referred to as "LL" or "LL load limiter") has a torsion bar (energy absorbing member) inside a spindle around which the webbing is wound, and one end of the torsion bar is connected to a locking member. When the locking member is locked, the spindle rotates according to the tension of the webbing, which causes a twist in the torsion bar, and the torsion bar is twisted by plastic deformation, absorbing energy. There is also a type (hereinafter, this may be referred to as "LLS") that has a stopper on the LL to forcibly stop the LL. There is also a type (hereinafter, this may be referred to as "LLS") that has a bending element on the LL, and in the early stages of a collision, the bending element's squeeze (friction) increases the load limiter load (energy absorption load), and in the later stages of a collision, the bending element's squeeze is released to allow the LL to function as a normal LL (energy absorption by a torsion bar) (hereinafter, this may be referred to as "LLD" or "two-stage load limiter"). There is also a type in which a torque tube or the like is provided in the LL, and a high load limiter load is set when the occupant is large, and a low load limiter load is set when the occupant is small (hereinafter, this may be referred to as "LLA" or "variable load limiter"). In the LLA, for example, if a high load limiter load is set as the default and a small occupant is detected, the MGG (micro gas generator) is activated at the moment of collision to switch to a low load limiter load. There is also a type in which an LLS is combined with an LLD or LLA (hereinafter, this may be referred to as "LLDS" or "LLAS"). Furthermore, the LLS, LLD, and LLA can be combined with each other, and there are also types that combine all of them.

[0004] The energy absorption mechanism described in Patent Document 2 is an LLA type that uses two torsion bars with different shaft diameters. The load limiter load can be switched between two levels, with a thick torsion bar setting a high load limiter load and a thin torsion bar setting a low load limiter load. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-250529 [Patent Document 2] International Publication No. 2016 / 063634 Summary of the Invention [Problem to be solved by the invention]

[0006] Occupants vary not only in weight and physique, but also in skeletal strength and internal organ resistance levels. If the load limiter load could be switched between more than two stages, it would be possible to accommodate a wide range of occupants, and the occupant restraint performance would be further improved. However, a system that adjusts the load limiter load steplessly would be complicated. In addition, a system that controls the webbing withdrawal speed would also be complicated.

[0007] An object of the present invention is to provide a seat belt retractor system that has a relatively simple configuration and is capable of responding to various conditions of restraint performance depending on the occupant. [Means for solving the problem]

[0008] A seat belt retractor according to one embodiment of the present invention is a seat belt retractor system including a retractor having a first energy absorption mechanism that enables the webbing to be unwound while absorbing energy when a load exceeding a predetermined value is applied to the webbing, and further includes an additional energy absorption mechanism that enables the webbing to be unwound while absorbing energy when a load exceeding a second predetermined value different from the predetermined value is applied to the webbing on a routing path of the webbing extended from the retractor, and the additional energy absorption mechanism is configured to be independently and selectively operable from the first energy absorption mechanism.

[0009] According to this aspect, it is possible to select whether or not to operate the additional energy absorption mechanism, and when operating the additional energy absorption mechanism, the additional energy absorption mechanism can be operated independently of the first energy absorption mechanism. When the additional energy absorption mechanism is not operated, the energy absorption load is the energy absorption load of the first energy absorption mechanism. On the other hand, when the additional energy absorption mechanism is operated, the energy absorption load of the additional energy absorption mechanism can be added to the energy absorption load of the first energy absorption mechanism. This means that if the first energy absorption mechanism can switch the energy absorption load in two stages, the switchable energy absorption load can be set to at least four stages. Therefore, with a relatively simple configuration, it is possible to respond to restraint performance under various conditions depending on the occupant. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing an example of a seat of a vehicle equipped with a seat belt retractor system according to an embodiment; [Diagram 2] 2 is a diagram showing a seat belt assembly including a retractor and a clamp EA in the seat belt retractor system of FIG. 1. FIG. [Diagram 3]1A and 1B are diagrams showing an LLA load limiter, which is an example of an energy absorption mechanism for a retractor. FIG. 1A shows the load transmission path when the load limiter load is set to a high level, and FIG. 1B shows the load transmission path when the load limiter load is set to a low level. [Figure 4] 1 is a perspective view showing an example in which the clamp EA according to the first embodiment is fixed to a retractor frame. FIG. [Diagram 5] FIG. 2 is a perspective view showing a state in which parts constituting the clamp EA according to the first embodiment are disassembled, together with a retractor. [Figure 6] 1 is a perspective view showing a state in which a clamp frame is removed from the clamp EA according to the first embodiment, together with a retractor. FIG. [Figure 7] 1 is a cross-sectional view of the clamp EA according to the first embodiment in an initial position, taken along a line passing through a shaft portion of a clamp member. FIG. [Figure 8] FIG. 2 is a cross-sectional view of the clamp EA according to the first embodiment in an initial position, taken along a line passing through the center (shear pin) of the clamp member. [Figure 9] 1A to 1C are schematic diagrams showing an overview of the operation of the clamp EA according to the first embodiment, in which (a) is an initial position, (b) is a diagram showing the start of operation, and (c) is a diagram showing the state during energy absorption. [Figure 10] 5A to 5D are cross-sectional views showing details of the operation of the clamp EA according to the first embodiment, in which (a) is an initial position, (b) is the start of operation, (c) is during energy absorption, and (d) is a view showing after energy absorption (clamp release). [Figure 11] FIG. 4 is a diagram showing an overview of combinations of load limiter loads in the retractor system according to the first embodiment. [Figure 12] 12 is a diagram showing an outline of a load acting on a webbing in the case of each load limiter load in FIG. 11. [Figure 13] 13 is a diagram showing an overview of a load acting on a webbing when an LLD is used instead of the LLA load limiter of FIG. 12. FIG. [Figure 14] 13A and 13B are diagrams illustrating a clamp EA according to a second embodiment. [Figure 15]FIG. 13 is a diagram showing an overview of a clamp EA according to a third embodiment. [Figure 16] FIG. 11 is a diagram showing an overview of combinations of load limiter loads in the retractor system according to the third embodiment. [Figure 17] FIG. 11 is a perspective view showing a state in which parts constituting a clamp EA according to a third embodiment are disassembled, together with a retractor. [Figure 18] FIG. 13 is a front view of a state in which the clamp EA according to the third embodiment is fixed to a retractor frame. [Figure 19] 19 is a cross-sectional view taken along the line AA in FIG. 18. [Figure 20] 13A to 13C are cross-sectional views showing the flow of operation of a clamp EA according to a third embodiment, in which (a) shows the start of operation, (b) shows energy absorption, and (c) shows after energy absorption (clamp release). [Figure 21] An enlarged oblique view showing the clutch disengagement operation of the clamp EA in the third embodiment, where (a) shows the initial position (clutch connected state), (b) shows a point immediately after a frontal collision of the vehicle, and (c) shows a point a short time after (b). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A preferred embodiment of the present invention will now be described with reference to the accompanying drawings.

[0012] In this document, up / down, left / right, and front / rear are defined as follows: When an occupant sits in a seat (vehicle seat) in a normal position, the direction the occupant faces is referred to as forward, and the opposite direction is referred to as rearward, and when indicating the axes of coordinates, they are referred to as the front / rear direction. Also, when an occupant sits in a vehicle seat in a normal position, the right side of the occupant is referred to as the right direction, and the left side of the occupant is referred to as the left direction, and when indicating the axes of coordinates, they are referred to as the left / right direction. Similarly, when an occupant sits in a normal position, the direction of the occupant's head is referred to as upward, and the direction of the occupant's waist is referred to as downward, and when indicating the axes of coordinates, they are referred to as the up / down direction.

[0013] In addition, EA is an abbreviation for Energy Absorption. EA load is an abbreviation for energy absorption load, and is synonymous with load limiter load or force limiter load. EA load refers to a limit load (load that limits the pull-out of the webbing) that represents the limit amount of the load acting on the webbing.

[0014] [Vehicle seat] 1 is a diagram showing an example of a vehicle seat 1. The vehicle seat 1 may be a front seat (i.e., a driver's seat or a passenger seat) or a rear seat. The vehicle seat 1 includes a seat back 2 that supports the back of an occupant, a seat cushion 3 on which the occupant sits, and a headrest 4 that supports the head of the occupant.

[0015] As is well known, the vehicle may be equipped with sensors and systems for detecting an occupant seated in the vehicle seat 1. For example, a weight sensor 5 for detecting the weight of the occupant may be provided on the seat cushion 3. Also, a physique sensor 6 (such as a strain gauge) for detecting the physique of the occupant (adult, child, etc.) may be provided on the seat cushion 3. Also, a camera 7 for capturing an image of the occupant may be provided, and the weight and / or physique of the occupant may be detected by analyzing the image generated by the camera 7 with a control device 8 (ECU).

[0016] The control device 8 is configured as, for example, a microcomputer, and includes a CPU, a memory, and an input / output interface. The CPU executes desired calculations according to a control program, and performs various processes and controls. The memory includes, for example, a ROM and a RAM. The ROM stores the control program and control data to be processed by the CPU, and the RAM is mainly used as various work areas for control processes. In addition to the weight sensor 5, the body size sensor 6, and the camera 7, a collision sensor 9 that detects a vehicle collision and various actuators (actuator 55 and LPAs 161, 761, 861, described later) are electrically connected to the input / output interface. The collision sensor 9 is for detecting a vehicle collision, and various known types of sensors, such as an acceleration sensor or a pressure sensor, can be used.

[0017] The control device 8 determines the weight and / or physique of the occupant seated in the vehicle seat 1 based on information from sensing devices such as the weight sensor 5, the physique sensor 6, or the camera 7. Depending on the determination result, the control device 8 selects one of a plurality of selectable EA loads as the EA load for restraining the occupant. Then, when the control device 8 receives an input signal from the collision sensor 9, that is, in the event of a vehicle emergency (when it determines whether or not the vehicle has collided forward and determines that a collision has occurred), it controls the seat belt assembly 10 (retractor 20, clamp EA 30) so that the selected EA load is applied.

[0018] [Seat belt assembly] A seat belt assembly 10 is provided in association with a vehicle seat 1. The seat belt assembly 10 includes a webbing 11 that is a seat belt for restraining an occupant. The webbing 11 includes a shoulder belt portion 14 that extends from an upper guide loop or anchorage 12 to a tongue 13 and a lap belt portion 16 that extends from the tongue 13 to an anchorage 15. The tongue 13 may include a loop portion 17 through which the webbing 11 extends. The tongue 13 is configured to be insertable into a buckle 18 to lock and unlock the seat belt assembly 10. A cable 19 of the buckle 18 secures the buckle 18 to a portion of the vehicle structure (e.g., a vehicle frame) directly or in cooperation with other components. When the tongue 13 is inserted into the buckle 18 and fastened, the seat belt assembly 10 defines a three-point restraint between the anchorage 12, the tongue 13, and the anchorage 15.

[0019] As shown in FIGS. 1 and 2, the seat belt assembly 10 includes a retractor 20 and a clamp EA30.

[0020] [Retractor] The retractor 20 can basically adopt a known configuration. The retractor 20 is configured to be able to retract the webbing 11, so that the effective length of the webbing 11 can be adjusted. The retractor 20 is positioned within the vehicle seat 1 or structurally coupled to the vehicle body.

[0021] 2, the retractor 20 has a retractor frame 21 and a spindle 22 rotatably housed in the retractor frame 21. The spindle 22 engages with the shoulder belt portion 14 of the webbing 11 and rotates to wind or unwind the webbing 11. The spindle 22 biases the webbing 11 in the winding direction by a power spring, an electric motor, or the like. Meanwhile, an end of the lap belt portion 16 of the webbing 11 is fixed to an anchorage 15 (for example, the retractor frame 21, the vehicle seat 1, or another part of the vehicle such as a floor pan).

[0022] The retractor 20 includes a pretensioner 40, a locking mechanism, and a torsion bar. Known configurations can be adopted for the pretensioner 40, the locking mechanism, and the torsion bar. An example will be described.

[0023] The pretensioner 40 is actuated, for example, in a vehicle emergency, and pulls the webbing 11 by rotating the spindle 22 in a direction in which the webbing 11 is wound, thereby removing slack in the webbing 11. The pretensioner 40 as an example has a rod movable inside the gas tube 42, and a gas generator 44 (micro gas generator (MGG)) at the end of the gas tube 42. The gas generator 44 is electrically connected to the control device 8, and is actuated upon receiving a signal from the control device 8 that detects a vehicle emergency situation. With this configuration, the pretensioner 40 actuates the gas generator 44 in a vehicle emergency, moves the rod inside the gas tube 42 by the gas generated thereby, engages the tip of the rod with the spindle 22 directly or via another member, and rotates the spindle 22 in the winding direction. As a result, the webbing 11 is wound, removing the slack, and reducing the forward movement or displacement of the occupant.

[0024] As is known, the locking mechanism restricts the rotation of the locking member (locks the locking member) to lock the rotation of the spindle 22 and thereby stops the unwinding of the webbing 11 when, for example, the vehicle decelerates at a predetermined rate or the brakes are applied with a predetermined force. The locking mechanism also locks the rotation of the spindle 22 in the event of a vehicle emergency. As a result, the occupant is fixed to the vehicle seat 1. Note that during normal operation of the vehicle, the retractor 20 allows the unwinding of the webbing 11 to give the occupant a certain degree of freedom of movement, and the webbing 11 may become slack during normal use.

[0025] As is known, the torsion bar constitutes an energy absorption mechanism (load limiter) that keeps the restraining force of the webbing 11 applied to the occupant at a constant level during a front collision of the vehicle. For example, in the LL load limiter, the torsion bar is disposed inside the spindle 22, one end is connected to the spindle 22, and the other end is connected to a lock member of the lock mechanism. When the lock member is locked during a front collision of the vehicle, the rotation of the spindle 22 is locked, but when the occupant is displaced forward in the vehicle cabin due to inertia, the tensile load acting on the webbing 11 increases. When this load exceeds a predetermined value, the spindle 22 rotates in response to the pulling of the webbing 11, which generates a twist in the torsion bar. The torsion bar is twisted by plastic deformation, so that energy is absorbed and the impact on the occupant's chest is mitigated. That is, the retractor 20 has an energy absorption mechanism 24 that enables the webbing 11 to be unwound while absorbing energy when a load exceeding a predetermined value is applied to the webbing 11.

[0026] [LLA Load Limiter (Energy Absorption Mechanism)] 3 shows an LLA load limiter 50 which is another example of the energy absorption mechanism 24. As described above, the LLA load limiter 50 is an LL load limiter to which a torque tube 57 and the like are additionally provided, and the load limiter load can be set in two stages. For example, the LLA load limiter 50 can be set to a high load limiter load when the occupant is large, and can be set to a low load limiter load when the occupant is small. The LLA load limiter 50 is also a known configuration, so the following will only briefly explain the outline of the configuration and the load transmission path.

[0027] First, in the LLA load limiter 50, a thick torsion bar 51 and a thin torsion bar 52 are connected in series. One end of the thick torsion bar 51 is connected to a tread head 53. The spindle 22 is connected at two points: one end of the thin torsion bar 52 and a connection part 54 between the thick torsion bar 51 and the thin torsion bar 52. An actuator 55 selects whether the connection part 54 is connected or disconnected to switch the load (torque).

[0028] As shown in FIG. 3(A), when a high load limiter load (high predetermined value) is set, the connection portion 54 is also connected to the spindle 22. In this case, the tensile load acting on the webbing 11 is transmitted to the spindle 22, the locking member 56, the torque tube 57, the thick torsion bar 51, and the tread head 53, in this order. At this time, the thick torsion bar 51 is twisted by the tensile load acting on the webbing 11, and energy is absorbed. On the other hand, as shown in FIG. 3(B), when a low load limiter load (low predetermined value) is set, the connection portion 54 is separated from the spindle 22. In this case, the tensile load acting on the webbing 11 is transmitted to the spindle 22, the thin torsion bar 52, the thick torsion bar 51, and the tread head 53. At this time, only the thin torsion bar 52 is twisted by the tensile load acting on the webbing 11, and energy is absorbed.

[0029] In the LLA load limiter 50, for example, a high load limiter load is set as a default. In the default setting, the actuator 55 is not actuated. The actuator 55 is actuated by an actuation signal from the control device 8, and may be, for example, a micro gas generator using explosives. In the LLA load limiter 50, when it is determined that the weight or physique of the occupant is small, it is set to switch to a low load limiter load. This is achieved by actuating the actuator 55 at the moment of a frontal collision, thereby separating the connection portion 54 from the spindle 22.

[0030] [Clamp EA Overview] 2 again, the retractor system of this embodiment includes a clamp EA 30 in addition to the retractor 20 having the energy absorption mechanism 24. The energy absorption mechanism 24 is, for example, an LLA load limiter 50. However, any known energy absorption mechanism, such as LL, LLS, LLD, LLDS, or LLAS, can be used for the energy absorption mechanism 24.

[0031] The clamp EA30 is an additional energy absorption mechanism provided on the crawling path 60 of the webbing 11 extending from the retractor 20. Like the energy absorption mechanism 24 of the retractor 20, the clamp EA30 enables the webbing 11 to be paid out while absorbing energy when a load exceeding a certain set value is applied to the webbing 11. However, this set value (second predetermined value) is different from the set value (first predetermined value, for example, the above-mentioned high load limiter load and low load limiter load) in the energy absorption mechanism 24. In addition, the clamp EA30 is configured to be independently and selectively operable from the energy absorption mechanism 24 (details will be described later).

[0032] The path 60 for the webbing 11 includes a first path 61 in which the webbing 11 extends from the retractor 20 in a first direction (here, upward), an anchorage 12 (through anchor) that is provided at an end of the first path 61 and can guide the webbing 11 to fold back in a second direction (here, downward or diagonally downward), and a second path 62 in which the folded back webbing 11 extends. The clamp EA30 is provided on the first path 61 and is located between the retractor 20 and the anchorage 12. In this case, the clamp EA30 may be structurally fixed to the vehicle body at a position away from the retractor 20. Alternatively, the clamp EA30 may be attached to a frame extension portion that extends from the retractor frame 21 in the first direction (here, upward). An example in which the clamp EA30 is fixed to the retractor frame 21 will be described below.

[0033] [First embodiment] [Clamp EA Details] 4 shows an example in which the clamp EA30 is fixed to the retractor frame 21. The clamp EA30 is fixed to the upper part of the retractor frame 21 so as to protrude upward from the retractor 20.

[0034] FIG. 5 is an exploded perspective view of parts constituting the clamp EA30. FIG. 6 shows the clamp EA30 with the clamp frame 110 removed. Also, FIGS. 7 and 8 are cross-sectional views of the clamp EA30 in the initial position (when the clamp EA30 is not in operation). Of these, FIG. 7 is a cross-sectional view taken at a position passing through the shaft portion 133 of the clamp member 130, and FIG. 8 is a cross-sectional view taken at a position passing through the center (shear pin 136) of the clamp member 130. The configuration of the clamp EA30 will be described below with reference to FIG. 5 as the main reference. Please refer to FIGS. 4 and 6 to 8 as appropriate.

[0035] The clamp EA30 includes a clamp frame 110 (mounting frame), a lower plate 120 (receiving member), a clamp member 130, a bar member 140 (connecting member), an EA plate 150 (energy absorbing member), an actuator unit 160, a lever 170, a guide 180, and a pin 190.

[0036] The clamp frame 110 has opposing side walls 111a, 111b and a bottom wall 112 connecting the side walls. The side walls 111a, 111b are formed with guide holes 113a, 113b extending in the vertical direction, as well as mounting holes 114, 115, 116 for mounting various parts. Both ends of the bar member 140 are inserted into the guide holes 113a, 113b. Both ends of the EA plate 150 are fixed into the mounting holes 114, 114. Both ends of the pin 190 are journaled in the mounting holes 115, 115. The mounting holes 116, 116 are used for fixing to the retractor frame 21. That is, the clamp EA 30 is attached to the retractor frame 21 via the clamp frame 110. A plate 118 having a webbing insertion hole 117 formed therein is attached to the upper ends of the side walls 111a, 111b and the bottom wall 112. The webbing insertion hole 117 is formed in a horizontally elongated slit shape, through which the webbing 11 is inserted (see FIG. 7).

[0037] The lower plate 120 has fixing holes 121, 122 at diagonal positions. The lower plate 120 is fixed to the bottom wall 112 of the clamp frame 110 via the fixing holes 121, 122. The lower plate 120 also has two regions 123, 124 with different plate thicknesses on the side opposite the bottom wall 112. The thin region 124 is located above the thick region 123, and the surface facing the clamp member 130 is formed to be thin.

[0038] The clamp member 130 has a wedge-shaped structure made up of a pressing surface 131 and a guide surface 132, and has a pair of shafts 133, 133 on the side opposite to the tip side of the wedge. A large number of locking projections 135 capable of locking with the webbing 11 are formed on the pressing surface 131 (see FIG. 7). The guide surface 132 faces the bar member 140. The guide surface 132 is configured to be slidable on a guide surface 142 of the bar member 140.

[0039] A shear pin 136 protrudes from the center of the guide surface 132. The shear pin 136 is inserted into the bar member 140 (see FIG. 8). The shear pin 136 is broken by a shear force acting when the clamp member 130 starts to slide relative to the bar member 140. In other words, the clamp member 130 is held to the bar member 140 by the shear pin 136 before the sliding starts. When a force is input from the outside to the shaft portion 133, the clamp member 130 breaks the shear pin 136 and becomes slidable relative to the bar member 140 (see FIG. 9).

[0040] The bar member 140 has a flat fixed surface 141 and an inclined guide surface 142 on the opposite side to the fixed surface 141. A plurality of (four here) fixing holes 143 are formed in the fixed surface 141. The fixed surface 141 faces the EA plate 150 and is fixed to the EA plate 150 via the fixing holes 143. The guide surface 142 faces the guide surface 132 of the clamp member 130 and guides the movement of the clamp member 130 towards the webbing 11 (see FIG. 7).

[0041] The bar member 140 is also movable in the up-down direction within the range of the up-down length of the guide holes 113a, 113b of the clamp frame 110. In the initial position, the lower end 144 of the bar member 140 abuts against the lower ends of the guide holes 113a, 113b. When the bar member 140 moves upward, it moves upward along the guide holes 113a, 113b while being guided by them. Then, when the upper end 145 of the bar member 140 abuts against the upper ends of the guide holes 113a, 113b, the movement of the bar member 140 is restricted.

[0042] The EA plate 150 is formed into a predetermined shape by, for example, bending a metal plate, and has a U-shaped portion 151. The U-shaped portion 151 has a flat fixed portion 152 and a pair of curved portions 153, 153. The fixed portion 152 is fixed to the fixed surface 141 of the bar member 140. One end of each of the pair of curved portions 153, 153 is connected to both sides of the lower end of the fixed portion 152, and extends upward from there in a U-shaped curve, and the other end of the extension is connected to a flat bridge portion 154. The bridge portion 154 is parallel to the fixed portion 152 at a position above the fixed portion 152. On both sides of the bridge portion 154, side pieces 155, 155 are formed by bending toward the opposite side to the fixed portion 152. A fixing hole 156 is formed through the side piece 155. Furthermore, a hook piece 157 is formed facing outward at the upper end of the side piece 155. The EA plate 150 is fixed with its fixing holes 156, 156 aligned with the mounting holes 114, 114 of the side walls 111a, 111b, and the hook pieces 157, 157 are hooked onto the upper ends of the side walls 111a, 111b. In the EA plate 150, the pair of curved portions 153, 153 are plastically deformed to absorb energy.

[0043] The actuator unit 160 includes an LPA (Linear Pilot Actuator) 161, which is an actuator, a housing 162, and a piston 163. The LPA 161 is a drive source for actuating the clamp EA30, and may be, for example, an electromagnetic actuator or a pyrotechnic actuator. The LPA 161 is actuated by receiving an actuation signal from the control device 8. The housing 162 accommodates the LPA 161 and the piston 163 below it in a cylindrical interior. The piston 163 moves downward of the housing 162 by the actuation of the LPA 161. In the initial position, the lower end of the piston 163 faces or abuts against the lever 170 (see FIG. 8). When the piston 163 moves downward by the actuation of the LPA 161, the piston 163 inputs a force to the lever 170, causing the lever 170 to rotate.

[0044] The lever 170 has an abutment portion 171, an input portion 172, and a rotating shaft portion 173. The abutment portion 171 abuts against the piston 163 and receives a force from the piston 163. The input portion 172 is provided on the opposite side of the rotating shaft portion 173 to the abutment portion 171. There are a pair of input portions 172, each of which abuts against the shaft portion 133 of the clamp member 130 and inputs a force to move the clamp member 130 to the shaft portion 133. There are a pair of rotating shaft portions 173, each of which has a pin 190 inserted through its center. Both ends of the pin 190 are supported by the side walls 111a, 111b of the clamp frame 110. Thus, the lever 170 is supported by the clamp frame 110 so as to be rotatable around the rotating shaft portion 173 (pin 190).

[0045] The guide 180 has a webbing insertion slit 181 and an insertion shaft portion 182. The webbing insertion slit 181 is formed in a horizontally long slit shape, and the webbing 11 is inserted therethrough (see FIG. 7). The webbing insertion slit 181 guides the webbing 11 immediately after it is unwound from the retractor 20. Three insertion shaft portions 182 are formed at intervals from each other. The rotation shaft portion 173 of the lever 170 is located in the space between the adjacent insertion shaft portions 182, 182. A pin 190 is inserted through the center of the insertion shaft portion 182. The guide 180 is fixed by inserting a tip portion 183 on the opposite side to the insertion shaft portion 182 into the bottom wall 112 of the clamp frame 110. Therefore, the guide 180 is fixed to the clamp frame 110 via the tip portion 183 and the insertion shaft portion 182 (pin 190).

[0046] [Outline of operation of EA30 clamp] 9A to 9C are schematic diagrams showing an overview of the operation of the clamp EA 30. In the initial position shown in FIG.

[0047] As shown in FIG. 9(b), when the LPA 161 is actuated, the lever 170 is rotated via the piston 163. Then, the clamp member 130 is pushed in by the lever 170, and its movement toward the webbing 11 is guided by the guide surface 142 of the bar member 140. At this time, the shear pin 136 breaks. When the clamp member 130 moves toward the webbing 11, the locking projection 135 locks onto (pierces) the webbing 11. As a result, the locking projection 135 is fixed to the webbing 11.

[0048] Thereafter, the clamp member 130 fixed to the webbing 11 via the locking projection 135 attempts to move in the direction of the arrow 200 as shown in FIG. 9(c) due to the tension of the webbing 11 (the force in the direction of being pulled out from the spindle 22). The webbing tension applied to the clamp member 130 acts on the guide surface 142 of the bar member 140 from the guide surface 132 of the clamp member 130, and attempts to move the bar member 140 in the direction of the arrow 200. As a result, the clamp member 130 and the bar member 140 move together in the direction of the arrow 200 while the U-shaped portion 151 (curved portion 153) of the EA plate 150 connected to the bar member 140 is plastically deformed. As a result, the energy acting on the webbing 11 is absorbed by the EA plate 150, and the webbing 11 is unwound.

[0049] In this manner, the EA plate 150 is switched from the non-energy absorbing mode (see FIG. 9(a)) to the energy absorbing mode (see FIG. 9(c)) by the actuation of the LPA 161. When the clamp EA30 is selected to be deactivated, the LPA 161 is not actuated, and the EA plate 150 is maintained in the non-energy absorbing mode (see FIG. 9(a)). In the non-energy absorbing mode, the locking projection 135 is separated from the webbing 11 as described above, and therefore the locking projection 135 does not affect the webbing 11.

[0050] [Details of the operation of the EA30 clamp] Next, the operation of the clamp EA30 will be described in detail with reference to FIG.

[0051] 10(a), the locking projection 135 of the clamp member 130 is separated from the webbing 11. The bar member 140 is positioned on the lower side in the guide hole 113a. The EA plate 150 is in the non-energy absorbing mode.

[0052] FIG. 10(b) shows the time when the LPA 161 is actuated. When the LPA 161 is actuated, the piston 163 moves downward to rotate the lever 170. When the lever 170 rotates, the input portion 172 of the lever 170 abuts against the shaft portion 133 of the clamp member 130 to move the clamp member 130. The clamp member 130 is guided in its movement upward toward the webbing 11 by the guide surface 142 of the bar member 140, and the locking projection 135 locks (pierces) into the webbing 11 and is fixed. That is, the clamp EA30 clamps the webbing 11. At this time, the locking projection 135 faces the thick region 123 of the lower plate 120 with the webbing 11 in between.

[0053] Fig. 10(c) shows energy being absorbed by the EA plate 150 in the energy absorbing mode. In the position shown in Fig. 10(c), the clamp member 130 has moved away from the input portion 172 of the lever 170, and the bar member 140 has moved to a vertically intermediate position in the guide hole 113a. This is because the clamp member 130 moves together with the bar member 140 in the direction of the arrow 210 due to the tension of the webbing 11 in the direction of the arrow 210, and with this movement, the U-shaped portion 151 (curved portion 153) of the EA plate 150 connected to the bar member 140 is pulled in the direction of the arrow 210 and plastically deformed. The location of plastic deformation shifts on the U-shaped portion 151 in accordance with the movement of the bar member 140. While this plastic deformation occurs, the webbing 11 is unwound while energy is absorbed. As the energy absorption by the EA plate 150 progresses, the portion of the locking projection 135 that faces the lower plate 120 with the webbing 11 sandwiched therebetween transitions from the thick region 123 to the thin region 124.

[0054] FIG. 10(d) shows a time when the clamp EA30 reaches the stroke end. The bar member 140 comes into contact with the upper end of the guide hole 113a due to the tension of the webbing 11 in the direction of the arrow 210, and the movement is restricted. Energy absorption by the EA plate 150 ends. All of the locking projections 135 have moved to positions facing the thin-walled region 124 with the webbing 11 sandwiched therebetween. Therefore, when tension of the webbing 11 is applied in the direction of the arrow 210, the webbing 11 comes off the lower plate 120 side, and the locking projections 135 come off the webbing 11. Since the webbing 11 is applied to the tip of the locking projection 135, the stress in the locking projection 135 changes from shear stress to bending stress and increases. The locking projection 135 cannot withstand the bending stress and breaks. As a result, the clamp EA30 releases the webbing 11 and releases the clamp.

[0055] As can be understood from the above description, in the lower plate 120, the thick region 123 (first region) holds the webbing 11 and the clamp member 130 engaged with the webbing 11, and the thin region 124 (second region) is located in the payout direction of the webbing 11 from the thick region 123, and promotes a tendency to release the engagement of the clamp member 130 with the webbing 11. If the lower plate 120 were not provided with the thin region 124, the engaging projection 135 would not come off the webbing 11 and would not break. In this case, although energy absorption by the EA plate 150 stops at the stroke end, the clamp is not released.

[0056] 10, the clamp EA30 is operated independently of the energy absorbing mechanism 24 of the retractor 20. This means that the operation of one of the clamp EA30 and the energy absorbing mechanism 24 is performed without affecting the operation of the other.

[0057] In addition, it is possible to select whether to activate the clamp EA30 or not (to deactivate it). This selection is made by the control device 8 in FIG. 1 according to the weight, physique, etc. of the occupant. When it is selected to activate the clamp EA30, the LPA 161 is activated at the time of a front collision of the vehicle, and the EA plate 150 is shifted to the energy absorbing mode. On the other hand, when it is selected not to activate the clamp EA30, the LPA 161 is not activated at the time of a front collision of the vehicle, and the EA plate 150 is maintained in the energy non-absorbing mode. In this case, the clamp EA30 does not affect the winding / unwinding of the webbing 11. In other words, the clamp EA30 does not come into contact with the webbing 11 in such a way as to change the winding force / unwinding force. Naturally, the clamp EA30 allows the unwinding of the webbing 11 without affecting the action (energy absorption) of the energy absorbing mechanism 24.

[0058] [Overview of Load Limiter Load Combinations] 11 is a diagram showing an overview of combinations of load limiter loads in the retractor system according to this embodiment. Here, an example is shown in which an LLA load limiter 50 is used as the energy absorption mechanism 24 of the retractor 20. With the LLA load limiter 50, the load limiter load can be selected in two stages, and it is possible to select whether or not to operate the clamp EA30. Therefore, a total of four load limiter loads can be selected, 2 stages x 2 stages.

[0059] FIG. 11(a) shows a combination of a high load limiter load due to a thick torsion bar 51 and a load limiter load when the clamp EA30 is actuated. FIG. 11(b) shows a case where the clamp EA30 is not actuated and a high load limiter load due to a thick torsion bar 51 is applied. Similarly, FIG. 11(c) shows a combination of a low load limiter load due to a thin torsion bar 52 and a load limiter load when the clamp EA30 is actuated. FIG. 11(d) shows a case where the clamp EA30 is not actuated, i.e., a low load limiter load due to a thin torsion bar 52 is applied. It will be understood that when the clamp EA30 is actuated, the load limiter load due to the clamp EA30 is added to the load limiter load due to the energy absorption mechanism 24.

[0060] Fig. 12 is a diagram showing an overview of the load acting on the webbing 11 in the case of each load limiter load in Fig. 11. In Fig. 12, a solid line indicates a case where the clamp EA30 is not actuated, and a dashed line indicates a case where the clamp EA30 is actuated. Fig. 12 also shows, for reference, a case where a stopper is provided on the LLA load limiter 50. The stopper can be provided to forcibly stop the LLA load limiter 50 so that the occupant does not move too far forward during a collision. It can be understood that the load acting on the webbing 11 becomes high because the stopper is forcibly stopped.

[0061] Fig. 13 is a diagram showing an overview of the load acting on the webbing 11 when an LLD is used instead of the LLA load limiter 50. As in Fig. 12, in Fig. 13, the solid line indicates the case where the clamp EA30 is not actuated, and the dashed line indicates the case where the clamp EA30 is actuated. Also, for reference, a case where a stopper is provided on the LLD is shown. As in the case of the LLA load limiter 50, it will be understood that when the clamp EA30 is actuated, an additional load is added to the load limiter load by the LLS (energy absorption mechanism 24).

[0062] As described above, the retractor system according to this embodiment includes, in addition to the retractor 20 having the energy absorption mechanism 24, the clamp EA30 (additional energy absorption mechanism) that can be selectively operated independently of the energy absorption mechanism 24. This allows a plurality of loads for restraining an occupant to be selected with a relatively simple configuration, and can accommodate various conditions of restraint performance depending on the occupant. In particular, the control device 8 can select in advance whether to activate or deactivate the clamp EA30 depending on the weight, physique, etc. of the occupant, and can restrain the occupant with a load according to the weight, physique, etc. of the occupant in the event of a frontal collision of the vehicle.

[0063] Next, other embodiments will be described. Note that the other embodiments will be described by focusing on the differences from the first embodiment, and the same or similar reference numerals will be used to designate configurations common to the first embodiment, and descriptions thereof will be omitted.

[0064] [Second embodiment] 14 is a diagram showing a clamp EA300 according to the second embodiment. The energy absorbing member of the clamp EA300 is a torsion bar 310, rather than the above-mentioned EA plate 150. One end of the torsion bar 310 is connected to a pinion gear 320, and the other end is connected to a fixed element such as the clamp frame 110. A rack gear 330 meshes with the pinion gear 320, and the rack gear 330 is fixed to the bar member 140. That is, the torsion bar 310 and the clamp member 130 are actually connected to each other by three connecting members (the pinion gear 320, the rack gear 330, and the bar member 140).

[0065] The torsion bar 310 is switched from a non-energy absorbing mode to an energy absorbing mode by the operation of the LPA 161. When the LPA 161 is operated, the clamp member 130 moves via the lever 170, and the locking projection 135 locks the webbing 11. Then, the clamp member 130, the bar member 140, and the rack gear 330 move upward in the figure due to the tension of the webbing 11, causing the pinion gear 320 to rotate. As a result, a torsion moment acts on one end of the torsion bar 310. The torsion bar 310 is twisted by plastic deformation, and the webbing 11 is unwound while the energy acting on the webbing 11 is absorbed by the torsion bar 310.

[0066] Here, the number of torsion bars 310 may be one or more. For example, the pinion gear 320 and the rack gear 330 may be disposed at the center of the clamp frame 110, and the torsion bars 310, 310 may be disposed on both sides of the pinion gear 320. This improves the balance of the load compared to a case where the torsion bar 310 is provided only on one side of the pinion gear 320. In addition, the thickness (diameter) of the torsion bars 310, 310 disposed on both sides of the pinion gear 320 can be made different from each other, which allows for subtle torque adjustment.

[0067] [Third embodiment] [Clamp EA Overview] 15 is a diagram showing an outline of a clamp EA400 according to the third embodiment. In the clamp EA400, clutches 500 and 600 are added to the torsion bars 411 and 412 disposed on both sides of a pinion gear 420, as compared to the clamp EA300 according to the second embodiment.

[0068] The clamp EA 400 has a pinion gear 420 and a rack gear 430 at the center of the clamp frame 110, with one end of a thick torsion bar 411 connected to the left half of the pinion gear 420 and one end of a thin torsion bar 412 connected to the right half of the pinion gear 420. The other end of the thick torsion bar 411 is supported by a side wall 111a of the clamp frame 110 via a clutch 500, and the other end of the thin torsion bar 412 is supported by a side wall 111b of the clamp frame 110 via a clutch 600. The clutches 500 and 600 switch the loads (torques) on the torsion bars 411 and 412, respectively.

[0069] Specifically, when the clutch 500 is engaged, the other end of the thick torsion bar 411 is connected to the side wall 111a, and the rotation of the pinion gear 420 causes the thick torsion bar 411 to plastically deform and absorb energy. When the clutch 500 is disengaged, the other end of the thick torsion bar 411 is disengaged from the side wall 111a. In this case, even if the pinion gear 420 rotates, the thick torsion bar 411 is not twisted and does not absorb energy. The same applies to the engagement and disengagement of the clutch 600, where the other end of the thin torsion bar 412 is switched between being connected and disconnected from the side wall 111b.

[0070] Therefore, the load limiter load that can be selected by clamp EA400 is four stages (when both clutches 500, 600 are connected, when only clutch 500 is connected, when only clutch 600 is connected, and when both clutches 500, 600 are disconnected).

[0071] [Overview of Load Limiter Load Combinations] Fig. 16 is a diagram showing an overview of combinations of load limiter loads in a retractor system according to the third embodiment. Here, as in the case of Fig. 11, an example is shown in which an LLA load limiter 50 is used as the energy absorption mechanism 24 of the retractor 20. With the LLA load limiter 50, two levels of load limiter load can be selected, and it is possible to select whether or not to operate the clamp EA 400, and further, which clutches 500, 600 are to be separated (turned ON) if the clamp EA 400 is to be operated. Thus, a total of eight levels of load limiter load can be selected, 2 levels x 4 levels.

[0072] In FIG. 16, "ON" and "OFF" mean the following. "OFF" for the LLA load limiter 50 means that a high load limiter load set by default is used. "ON" for the LLA load limiter 50 means that a low load limiter load set by operating the actuator 55 is used. "OFF" for the clamp EA 400 means that the clamp EA 400 is not operated, and "ON" for the clamp EA 400 means that the clamp EA 400 is operated. "ON" for the clutch 500 means that the clutch 500 is operated to separate, that is, energy absorption by the thick torsion bar 411 is not performed, and a load limiter load by the thin torsion bar 412 is added. "OFF" for the clutch 500 means that the clutch 500 is not operated and the clutch 500 is kept connected, that is, a load limiter load by the thick torsion bar 411 is added. The "ON" and "OFF" states of the clutch 600 are similar to those of the clutch 500.

[0073] Here, various mechanisms can be used for the clutches 500 and 600. For example, it is possible to repurpose the switching mechanism in the LLA load limiter 50. This type of switching mechanism is already known, but an outline will be described with reference to Fig. 17 onwards.

[0074] [Clamp EA Details] Fig. 17 is an exploded perspective view of parts constituting the clamp EA400. Fig. 18 is a front view of the clamp EA400 fixed to the retractor frame 21, and Fig. 19 is a cross-sectional view taken along line AA in Fig. 18 (a cross-sectional view passing through the center of the clamp EA400). In Fig. 17, a thick torsion bar 411, a thin torsion bar 412, a pinion gear 420, a rack gear 430, clutches 500, 600, and actuator units 700, 800 are used compared to Fig. 5. Also, the shapes of the side walls 111a, 111b of the clamp frame 110 are changed. Specifically, mounting openings 900a, 900b are formed in the side walls 111a, 111b.

[0075] The torsion bars 411, 412 each have a first torque transmission portion 414, 415 at the other end opposite the pinion gear 420. The torsion bars 411, 412 also have a second torque transmission portion 416 that connects the torsion bars 411, 412 to each other at one end on the pinion gear 420 side. The torque transmission portions 414, 415, 416 can be configured in the shape of a serration or a spline.

[0076] The pinion gear 420 has a gear portion 421 that meshes with the rack gear 430 at the center of the outer periphery formed in a cylindrical shape. A portion of the torsion bars 411, 412 is inserted inside the pinion gear 420. A torque transmission portion 422 fastened to the second torque transmission portion 416 is formed inside the pinion gear 420 so that the rotational torque of the pinion gear 420 is transmitted to the torsion bars 411, 412 (see FIG. 19).

[0077] Clutch 500 has a bearing 510, a stopper 520, and a cam plate 530. Clutch 600 has a bearing 610, a stopper 620, and a cam plate 630. Since clutch 500 and clutch 600 have the same configuration, the following will describe clutch 500 in detail, and for clutch 600, the same components as those in clutch 500 will be denoted by the same reference numerals and description thereof will be omitted.

[0078] The bearing 510 has an inner torque transmission portion 511, an outer torque transmission portion 512, and an outer ring portion 513. The inner torque transmission portion 511 and the outer torque transmission portion 512 can be configured in the shape of serrations or splines. The first torque transmission portion 414 of the torsion bar 411 is connected to the inner torque transmission portion 511. The torque transmission portion 521 of the stopper 520 is connected to the outer torque transmission portion 512. The outer ring portion 513 is rotatably supported in the mounting opening 900a of the side wall 111a.

[0079] The stopper 520 is formed in a ring shape as a whole. A torque transmission part 521 is formed on the inside of the stopper 520, and is connected to an outer torque transmission part 512 of the bearing 510. A cam groove 522 is formed on the outer peripheral surface of the stopper 520. A pair of cam grooves 522 are formed at positions facing each other across the axis of the stopper 520. An engaging protrusion 523 is formed on the end of the axially outer side of the stopper 520. A pair of engaging protrusions 523 are formed at positions facing each other across the axis of the stopper 520. The cam groove 522 and the engaging protrusion 523 are offset from the axis of the stopper 520 by, for example, 90 degrees.

[0080] The cam plate 530 has a ring portion 531, a cam portion 532, and an input receiving portion 533. A bearing 510 and a stopper 520 are disposed inside the ring portion 531. The outer surface of the ring portion 531 abuts against the inner surface of the side wall 111a. The cam portion 532 protrudes in the axial direction from the inner peripheral surface of the ring portion 531. A pair of cam portions 532 are formed at positions facing each other across the axis of the cam plate 530. The pair of cam portions 532, 532 engage with the pair of cam grooves 522, 522, respectively. The input receiving portion 533 protrudes from the outer periphery of the ring portion 531. The input receiving portion 533 is configured to be able to input power from the actuator unit 700. When this power is input, the cam plate 530 receives a rotational force.

[0081] The mounting opening 900a of the side wall 111a has a circular portion 910a and an engagement receiving portion 920a. The bearing 510 is inserted from the outside of the circular portion 910a, and the outer ring portion 513 of the bearing 510 is rotatably supported on the inner peripheral surface of the circular portion 910a. A pair of engagement receiving portions 920 are formed at positions facing each other across the center of the mounting opening 900a. A pair of engagement protrusions 523 of the stopper 520 engages with the pair of engagement receiving portions 920a, 920a, respectively, in a disengageable manner.

[0082] The actuator units 700 and 800 are for disengaging the clutches 500 and 600, respectively. The actuator units 700 and 800 are configured similarly to the actuator unit 160, and each include an LPA 761 and 861, a housing 762 and 862, and a piston 763 and 863. The housings 762 and 862 can be provided in the same structure as the housing 162 of the actuator unit 160.

[0083] [When Clutch 500, 600 is connected (default setting)] In this case, as the load limiter load in the retractor system, the load limiter loads due to the torsion bars 411, 412 are added to the load limiter load due to the energy absorbing mechanism 24 of the retractor 20. The LPAs 761, 861 of the actuator units 700, 800 are not actuated.

[0084] FIG. 20 is a cross-sectional view showing the operation of the clamp EA 400, where (a) shows the start of operation, (b) shows the state during energy absorption, and (c) shows the state after energy absorption ends (the point at which the clamp EA 400 reaches the stroke end).

[0085] As shown in Fig. 20(a) , when the LPA 161 of the actuator unit 160 is actuated during a frontal collision of the vehicle, the clamp member 130 moves via the lever 170, and the locking projection 135 locks onto the webbing 11. Then, as shown in Fig. 20(b) , the tension of the webbing 11 causes the clamp member 130, the bar member 140, and the rack gear 430 to move upward in the figure, causing the pinion gear 420 to rotate. As a result, a rotational force is transmitted from the second torque transmission portion 416 of the pinion gear 420 to the torque transmission portions 422 at one ends of the torsion bars 411 and 412.

[0086] Here, since the other ends of the torsion bars 411, 412 are fixed to the clamp frame 110 via the bearings 510, 610 and the stoppers 520, 620, a torsion moment acts on one end of the torsion bars 411, 412. Specifically, the first torque transmission parts 414, 415 of the torsion bars 411, 412 are connected to the inner torque transmission parts 511 of the bearings 510, 610, the outer torque transmission parts 512, 612 of the bearings 510, 610 are connected to the torque transmission parts 521, 621 of the stoppers 520, 620, and the engaging protrusions 523, 623 of the stoppers 520, 620 are engaged with the engaging receiving parts 920a, 920b of the side walls 111a, 111b, so that the other ends of the torsion bars 411, 412 are fixed to the clamp frame 110. When a torsion moment acts on one end of the torsion bars 411, 412, the torsion bars 411, 412 are twisted by plastic deformation, and the energy acting on the webbing 11 is absorbed by the torsion bars 411, 412.

[0087] Thereafter, as shown in Fig. 20(c), the energy absorption by the clamp EA 400 ends. The operation of ending the energy absorption by the clamp EA 400 and releasing the clamp is the same as in the first embodiment (Fig. 10(d)).

[0088] [When separating the clutch 500] In this case, as the load limiter load in the retractor system, the load limiter load by the torsion bar 412 is added to the load limiter load by the energy absorbing mechanism 24 of the retractor 20. The load limiter load by the torsion bar 411 is not added. The LPA 861 of the actuator unit 800 is not activated.

[0089] Figure 21 is an enlarged oblique view showing the disengagement operation of clutch 500, where (a) shows the initial position (clutch 500 engaged state), (b) shows a point immediately after a frontal collision of the vehicle, and (c) shows a point a short time after (b).

[0090] 21(b), when the vehicle experiences a frontal collision, LPA 761 of actuator unit 700 is activated. Then, piston 763 moves out of housing 762 and comes into contact with input receiving portion 533 of cam plate 530, causing cam plate 530 to rotate. When cam plate 530 rotates, cam portion 532 of cam plate 530 interferes with cam groove 522 of stopper 520, causing stopper 520 to move in the thrust direction.

[0091] As shown in FIG. 21(c), when the cam plate 530 further rotates and the stopper 520 moves in the thrust direction, the engaging protrusion 523 of the stopper 520 disengages from the engaging receiving portion 920a of the side wall 111a. This separates (releases) the other end of the torsion bar 411 from the side wall 111a. Also, the torque transmission portion 521 of the stopper 520 disengages from the outer torque transmission portion 512 of the bearing 510 and is released from the connection. As a result, the torsion bar 411 to which the rotational force is input from the pinion gear 420 rotates together with the bearing 510, and is not twisted and does not absorb the energy acting on the webbing 11. In this case, only the torsion bar 412 to which the rotational force is input from the pinion gear 420 is twisted and absorbs the energy.

[0092] Although not described in detail, when the clutch 600 is to be disengaged, the LPA 861 of the actuator unit 800 is operated.

[0093] As described above, the retractor system according to the third embodiment allows more load settings and can accommodate restraint performance under a wider variety of conditions.

[0094] The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangements, materials, conditions, shapes, sizes, etc., are not limited to those exemplified, and may be modified as appropriate.

[0095] For example, in the modified example of the second embodiment, the pinion gear 320 and the rack gear 330 are positioned at the center of the clamp frame 110, and the torsion bars 310, 310 are positioned on either side of the pinion gear 320, but the pinion gear 320 and the rack gear 330 can also be positioned other than at the center of the clamp frame 110.

[0096] In the third embodiment, the clamp EA 400 includes both the first clutch 500 and the second clutch 600, but may include only one of them.

[0097] <Additional Considerations Regarding Various Implementations> [Embodiment 1] A seat belt retractor system including a retractor (20) having an energy absorption mechanism (24, 50) that can absorb energy and unwind the webbing (11) when a load exceeding a predetermined value is applied to the webbing (11), an additional energy absorption mechanism (30, 300, 400) that enables the webbing (11) to be unwound while absorbing energy when a load exceeding a second predetermined value different from the predetermined value is applied to the webbing (11) on a crawling path (60) of the webbing (11) extended from the retractor (20); A seat belt retractor system, wherein the additional energy absorbing mechanism (30, 300, 400) is configured to be selectively operable independently of the energy absorbing mechanism (24, 50).

[0098] [Embodiment 2] A seat belt retractor system according to embodiment 1, wherein the additional energy absorption mechanism (30, 300, 400), when selected to be deactivated, allows the webbing (11) to be unwound without affecting the action of the energy absorption mechanism (24, 50).

[0099] [Embodiment 3] The webbing (11) has a crawling path, a first path (61) through which the webbing (11) extends in a first direction from the retractor; a through anchor (12) provided at an end of the first path (61) and capable of guiding the webbing (11) to fold back in a second direction, 3. A seat belt retractor system according to claim 1 or 2, wherein the additional energy absorption mechanism (30, 300, 400) is provided in the first path (61).

[0100] [Embodiment 4] The additional energy absorbing mechanism (30, 300, 400) an actuator (161) that operates upon receiving an actuation signal; an energy absorbing member (150, 310, 411, 412) that is switched from a non-energy absorbing mode to an energy absorbing mode by the actuation of the actuator (161); The seat belt retractor system according to any one of embodiments 1 to 3, comprising:

[0101] [Embodiment 5] A seat belt retractor system according to embodiment 4, wherein the additional energy absorption mechanism (30, 300, 400), when selected to be deactivated, does not activate the actuator (161) and maintains the energy absorption member (150, 310, 411, 412) in the non-energy absorbing mode.

[0102] [Embodiment 6] A control device (8) for selecting whether to activate or deactivate the additional energy absorbing mechanism (30, 300, 400), A seat belt retractor system of embodiment 4 or 5, wherein the control device (8) selects to activate the additional energy absorption mechanism (30, 300, 400) and sends the activation signal to the actuator (161) upon a collision of a vehicle equipped with the seat belt retractor system.

[0103] [Embodiment 7] A seat belt retractor system according to embodiment 6, wherein the control device (8) selects whether to activate or deactivate the additional energy absorption mechanism (30, 300, 400) depending on the occupant seated in the vehicle seat (1).

[0104] [Embodiment 8] A seat belt retractor system according to embodiment 7, wherein the control device (8) selects whether to activate or deactivate the additional energy absorption mechanism (30, 300, 400) depending on at least one of the weight and body size of the occupant.

[0105] [Embodiment 9] The additional energy absorbing mechanism (30, 300, 400) a clamp member (130) that engages with the webbing by actuation of the actuator; one or more connecting members (140, 320, 330, 420, 430) connecting the clamping member and the energy absorbing member; Further equipped with A seat belt retractor system according to any one of embodiments 4 to 8, wherein when a load exceeding the second predetermined value is applied to the webbing (11), the energy absorption member (150, 310, 411, 412) deforms via the clamp member (130) and the connecting member (140, 320, 330, 420, 430) to absorb energy.

[0106] [Embodiment 10] The energy absorbing member (150) has a U-shaped portion (151), A part (152) of the U-shaped portion (151) is fixed to the connecting member (140), A seat belt retractor system according to embodiment 9, wherein when a load exceeding the second predetermined value is applied to the webbing (11), the other portion (153) of the U-shaped portion (151) of the energy absorbing member (150) plastically deforms via the clamp member (130) and the connecting member (140) to absorb energy.

[0107] [Embodiment 11] The energy absorbing member (310, 411, 412) has one or more torsion bars (310, 411, 412), The torsion bar (310, 411, 412) has one end connected to the connecting member (320, 420), A seat belt retractor system according to embodiment 9, wherein when a load exceeding the second predetermined value is applied to the webbing (11), a torsion moment is applied to the one end of the torsion bar (310, 411, 412) via the clamp member (130) and the connecting member (140, 320, 330, 420, 430) to absorb energy.

[0108] [Embodiment 12] The one or more torsion bars (411, 412) A first torsion bar (411); A second torsion bar (412), The one or more connecting members (140, 420, 430) a pinion gear (420) connected to one end of the first torsion bar (411) and one end of the second torsion bar (412); a rack gear (430) that meshes with the pinion gear; a bar member (140) provided between the rack gear and the clamp member, A seat belt retractor system according to embodiment 11, configured such that when a load exceeding the second predetermined value is applied to the webbing (11), the bar member (140) and the rack gear (430) move via the clamp member (130), thereby causing the pinion gear (420) to rotate, and the rotational force of the pinion gear (420) is transmitted to the first torsion bar (411) and the second torsion bar (412).

[0109] [Embodiment 13] The additional energy absorbing mechanism (400) comprises: a first clutch (500) capable of switching between a connected state in which the first torsion bar (411) to which the rotational force of the pinion gear (420) is transmitted can be subjected to a torsion moment without rotating, and a disconnected state in which the first torsion bar (411) is rotated and subjected to no torsion moment; a second clutch (600) capable of switching between a connected state in which the second torsion bar (412) to which the rotational force of the pinion gear (420) is transmitted can be subjected to a torsion moment without rotating, and a disconnected state in which the second torsion bar (412) is rotated and does not apply a torsion moment; A seat belt retractor system according to embodiment 12, further comprising at least one of the following:

[0110] [Embodiment 14] The additional energy absorption mechanism (30, 300, 400) further includes a receiving member (120) that faces the clamp member (130) with the webbing (11) sandwiched therebetween, The receiving member (120) is a first region (123) that clamps the clamp member (130) engaged with the webbing (11) and the webbing (11); A seat belt retractor system according to any one of embodiments 9 to 14, further comprising: a second region (124) located in the payout direction of the webbing (11) than the first region (123) and for encouraging the clamp member (130) to release the engagement with the webbing (11). [Explanation of symbols]

[0111] 1...vehicle seat, 2...seat back, 3...seat cushion, 4...headrest, 5...weight sensor, 6...body size sensor, 7...camera, 8...control device, 9...crash sensor, 10...seat belt assembly, 11...webbing, 12...anchorage, 13...tongue, 14...shoulder belt portion, 15...anchorage, 16...lap belt portion, 17...loop portion, 18...buckle, 19...cable, 20...retractor, 21...retractor frame, 22...spindle, 24...energy absorption mechanism, 30...clamp EA (additional energy absorption mechanism), 40...pretension a torque tube, 42...gas tube, 44...gas generator, 50...LLA load limiter (energy absorption mechanism), 51, 52...torsion bar, 53...tread head, 54...connection portion, 55...actuator, 56...lock member, 57...torque tube, 60...crawling path, 61...first path, 62...second path, 110...clamp frame, 111a, 111b...side wall, 112...bottom wall, 113a, 113b...guide hole, 114, 115, 116...mounting hole, 117...webbing insertion hole, 118...plate, 120...lower plate (receiving member), 121, 122...fixing Hole, 123... thick region (first region), 124... thin region (second region), 130... clamp member, 131... pressing surface, 132... guide surface, 133... shaft portion, 135... locking projection, 136... shear pin, 140... bar member (connecting member), 141... fixing surface, 142... guide surface, 143... fixing hole, 144... lower end, 145... upper end, 150... EA plate (energy absorbing member), 151... U-shaped portion, 152... fixing portion, 153... curved portion, 154... bridge portion, 155... side piece, 156... fixing hole, 157... latch piece, 160... actuator unit, 161... LPA, 162... Housing, 163... piston, 170... lever, 171... abutment portion, 172... input portion, 173... rotating shaft portion, 180... guide, 181... webbing insertion slit, 182... insertion shaft portion, 183... tip portion, 190... pin, 200, 210... arrow, 210... arrow, 300... clamp EA (additional energy absorption mechanism), 310... torsion bar (energy absorbing member), 320... pinion gear, 330... rack gear, 400... clamp EA (additional energy absorption mechanism), 411, 412... torsion bar, 414, 415... first torque transmission portion, 416... second torque transmission portion,420... pinion gear, 421... gear portion, 422... torque transmission portion, 430... rack gear, 500, 600... clutch, 510, 610... bearing, 511, 611... inner torque transmission portion, 512, 612... outer torque transmission portion, 513, 613... outer ring portion, 520, 620... stopper, 521, 621... torque transmission portion, 522, 622... cam groove, 523, 623... engagement Convex and concave portions, 530, 630...cam plate, 531, 631...ring portion, 532, 632...cam portion, 533, 633...input receiving portion, 700, 800...actuator unit, 761, 861...LPA, 762, 862...housing, 763, 863...piston, 900a, 900b...mounting opening, 910a, 910b...circular portion, 920a, 920b...engagement receiving portion,

Claims

1. A seat belt retractor system including a retractor having an energy absorption mechanism that is capable of unwinding a webbing while absorbing energy when a load exceeding a predetermined value is applied to the webbing, an additional energy absorption mechanism that enables the webbing to be unwound while absorbing energy when a load exceeding a second predetermined value different from the predetermined value is applied to the webbing on a path along which the webbing is extended from the retractor; The additional energy absorbing mechanism is configured to be selectively operable independently of the energy absorbing mechanism.

2. 2. The seat belt retractor system of claim 1, wherein the additional energy absorbing mechanism, when selected to be deactivated, allows the webbing to be unwound without affecting the action of the energy absorbing mechanism.

3. The webbing has a crawling path, a first path along which the webbing extends from the retractor in a first direction; a through anchor provided at an end of the first path and capable of guiding the webbing to fold back in a second direction, 2. The seat belt retractor system of claim 1, wherein the additional energy absorbing mechanism is provided in the first path.

4. The additional energy absorbing mechanism includes: an actuator that operates in response to receiving an actuation signal; an energy absorbing member that is switched from a non-energy absorbing mode to an energy absorbing mode by operation of the actuator; 2. The seat belt retractor system of claim 1, comprising:

5. 5. The seat belt retractor system of claim 4, wherein the additional energy absorbing mechanism, when selected to be deactivated, does not activate the actuator and maintains the energy absorbing member in the non-energy absorbing mode.

6. A control device is further provided for selecting whether to activate or deactivate the additional energy absorbing mechanism, 5. The seat belt retractor system according to claim 4, wherein when the control device selects to activate the additional energy absorption mechanism, the control device transmits the activation signal to the actuator when a collision occurs in a vehicle equipped with the seat belt retractor system.

7. 7. The seat belt retractor system according to claim 6, wherein the control device selects whether to activate or deactivate the additional energy absorbing mechanism depending on an occupant seated in the vehicle seat.

8. 8. The seat belt retractor system according to claim 7, wherein the control device selects whether to activate or deactivate the additional energy absorbing mechanism depending on at least one of a weight and a body size of the occupant.

9. The additional energy absorbing mechanism includes: a clamp member that is engaged with the webbing by actuation of the actuator; one or more connecting members connecting the clamping member and the energy absorbing member; Further equipped with 9. The seat belt retractor system according to claim 4, wherein when a load exceeding the second predetermined value is applied to the webbing, the energy absorbing member deforms via the clamp member and the connecting member to absorb energy.

10. The energy absorbing member has a U-shaped portion, A portion of the U-shaped portion is fixed to the connecting member, 10. The seat belt retractor system according to claim 9, wherein when a load exceeding the second predetermined value is applied to the webbing, another portion of the U-shaped portion of the energy absorbing member is plastically deformed via the clamp member and the connecting member to absorb energy.

11. The energy absorbing member includes one or more torsion bars. The torsion bar has one end connected to the connecting member, 10. The seat belt retractor system according to claim 9, wherein when a load exceeding the second predetermined value is applied to the webbing, a torsion moment is applied to the one end of the torsion bar via the clamp member and the connecting member, thereby absorbing energy.

12. The one or more torsion bars include A first torsion bar; a second torsion bar; The one or more connecting members include: a pinion gear connected to one end of the first torsion bar and one end of the second torsion bar; a rack gear that meshes with the pinion gear; a bar member provided between the rack gear and the clamp member, 12. The seat belt retractor system according to claim 11, wherein when a load exceeding the second predetermined value is applied to the webbing, the bar member and the rack gear move via the clamp member, thereby causing the pinion gear to rotate, and a rotational force of the pinion gear is transmitted to the first torsion bar and the second torsion bar.

13. The additional energy absorbing mechanism includes: a first clutch that can switch between a connected state in which a torsion moment can be applied to the first torsion bar, to which a rotational force of the pinion gear is transmitted, without rotating the first torsion bar, and a disconnected state in which the first torsion bar is rotated and no torsion moment is applied; a second clutch that can switch between a connected state in which a torsion moment can be applied to the second torsion bar, to which the rotational force of the pinion gear is transmitted, without rotating the second torsion bar, and a disconnected state in which the second torsion bar is rotated and no torsion moment is applied; 13. The seat belt retractor system of claim 12, further comprising at least one of:

14. The additional energy absorption mechanism further includes a receiving member that faces the clamp member with the webbing sandwiched therebetween, The receiving member is a first region that clamps the webbing and the clamp member engaged with the webbing; 10. The seat belt retractor system according to claim 9, further comprising: a second region located further in the unwinding direction of the webbing than the first region, for promoting a tendency for the clamp member to release the engagement of the webbing with the clamp member.

Images